Aims. The morphometry of the distal femur was largely studied to improve bone-implant fit in total knee arthroplasty (TKA), but little is known about the asymmetry of the posterior condyles. This study aimed to investigate the dimensions of the posterior condyles and the influence of externally rotating the femoral component on potential prosthetic overhang or under-coverage. Patients and Methods. We analysed the shape of 110 arthritic knees at the time of primary TKA using pre-operative CT scans. The height and width of each condyle were measured at the posterior femoral cut in neutral position, and in 3º and 5º of external rotation, using both central and medial referencing systems. We compared the morphological characteristics with those of 14 TKA models. Results. In the neutral position, the dimensions of the condyles were nearly equal. Externally rotating the femoral cut by 3º and 5º with ‘central referencing’ induced width asymmetry >  3 mm in 23 (21%) and 33 (30%) knees respectively, while with ‘medial referencing’ it induced width asymmetry > 3 mm in 43 (39%) and 75 (68%) knees respectively. The asymmetries induced by rotations were not associated with gender, aetiology or varus-valgus alignment. Conclusion. External rotation may amplify the asymmetry between the medial and lateral condyles, and exacerbate prosthetic overhang, particularly in the superolateral zone. ‘Central referencing’ guides result in less potential prosthetic overhang than ‘medial referencing’ guides. Cite this article: Bone Joint J 2017;99-B:894–903

In adults with brachial plexus injuries, lack of active external rotation at the shoulder is one of the most common residual deficits, significantly compromising upper limb function. There is a paucity of evidence to address this complex issue. We present our experience of isolated latissimus dorsi (LD) muscle transfer to achieve active external rotation. This is a retrospective review of 24 adult post-traumatic plexopathy patients who underwent isolated latissimus dorsi muscle transfer to restore external rotation of the shoulder between 1997 and 2010. All patients were male with a mean age of 34 years (21 to 57). All the patients underwent isolated LD muscle transfer using a standard technique to correct external rotational deficit. Outcome was assessed for improvement in active external rotation, arc of movement, muscle strength and return to work. The mean improvement in active external rotation from neutral was 24° (10° to 50°). The mean increase in arc of rotation was 52° (38° to 55°). Mean power of the external rotators was 3.5 Medical Research Council (MRC) grades (2 to 5). A total of 21 patients (88%) were back in work by the time of last follow up. Of these, 13 had returned to their pre-injury occupation. Isolated latissimus dorsi muscle transfer provides a simple and reliable method of restoring useful active external rotation in adults with brachial plexus injuries with internal rotational deformity. Cite this article: Bone Joint J 2013;95-B:660–3

We undertook a prospective study in 51 male patients aged between 17 and 27 years to ascertain whether immobilisation after primary traumatic anterior dislocation of the shoulder in external rotation was more effective than immobilisation in internal rotation in preventing recurrent dislocation in a physically active population. Of the 51 patients, 24 were randomised to be treated by a traditional brace in internal rotation and 27 were immobilised in external rotation of 15° to 20°. After immobilisation, the patients undertook a standard regime of physiotherapy and were then assessed clinically for evidence of instability. When reviewed at a mean of 33.4 months (24 to 48) ten from the external rotation group (37%) and ten from the internal rotation group (41.7%) had sustained a futher dislocation. There was no statistically significant difference (p = 0.74) between the groups. Our findings show that external rotation bracing may not be as effective as previously reported in preventing recurrent anterior dislocation of the shoulder

Aims. The effect of pelvic tilt (PT) and sagittal balance in hips with pincer-type femoroacetabular impingement (FAI) with acetabular retroversion (AR) is controversial. It is unclear if patients with AR have a rotational abnormality of the iliac wing. Therefore, we asked: are parameters for sagittal balance, and is rotation of the iliac wing, different in patients with AR compared to a control group?; and is there a correlation between iliac rotation and acetabular version?. Methods. A retrospective, review board-approved, controlled study was performed including 120 hips in 86 consecutive patients with symptomatic FAI or hip dysplasia. Pelvic CT scans were reviewed to calculate parameters for sagittal balance (pelvic incidence (PI), PT, and sacral slope), anterior pelvic plane angle, pelvic inclination, and external rotation of the iliac wing and were compared to a control group (48 hips). The 120 hips were allocated to the following groups: AR (41 hips), hip dysplasia (47 hips) and cam FAI with normal acetabular morphology (32 hips). Subgroups of total AR (15 hips) and high acetabular anteversion (20 hips) were analyzed. Statistical analysis was performed using analysis of variance with Bonferroni correction. Results. PI and PT were significantly decreased comparing AR (PI 42° (SD 10°), PT 4° (SD 5°)) with dysplastic hips (PI 55° (SD 12°), PT 10° (SD 6°)) and with the control group (PI 51° (SD 9°) and PT 13° (SD 7°)) (p < 0.001). External rotation of the iliac wing was significantly increased comparing AR (29° (SD 4°)) with dysplastic hips (20°(SD 5°)) and with the control group (25° (SD 5°)) (p < 0.001). Correlation between external rotation of the iliac wing and acetabular version was significant and strong (r = 0.81; p < 0.001). Correlation between PT and acetabular version was significant and moderate (r = 0.58; p < 0.001). Conclusion. These findings could contribute to a better understanding of hip pain in a sitting position and extra-articular subspine FAI of patients with AR. These patients have increased iliac external rotation, a rotational abnormality of the iliac wing. This has implications for surgical therapy with hip arthroscopy and acetabular rim trimming or anteverting periacetabular osteotomy (PAO). Cite this article: Bone Jt Open 2021;2(10):813–824

This study aimed to assess the effect of flexion and external rotation on measurement of femoral offset (FO), greater trochanter to femoral head centre (GT-FHC) distance, and neck shaft angle (NSA). Three-dimensional femoral shapes (n=100) were generated by statistical shape modelling from 47 CT-segmented right femora. Combined rotations in the range of 0–50° external and 0–50° flexion (in 10° increments) were applied to each femur after they were neutralised (defined as neck and proximal shaft axis parallel with detector plane). Each shape was projected to create 2D images representing radiographs of the proximal femora. As already known, external rotation resulted in a significant error in measuring FO but flexion alone had no impact. Individually, neither flexion nor external rotation had any impact on GT-FHC but, for example, 30° of flexion combined with 50°of external rotation resulted in an 18.6mm change in height. NSA averaged 125° in neutral with external rotation resulting in a moderate increase and flexion on its own a moderate decrease. However, 50° degrees of both produced an almost 30 degree increase in NSA. In conclusion, although the relationship between external rotation and FO is appreciated, the impact of flexion with external rotation is not. This combination results in apparent reduced FO, a high femoral head centre and an increased NSA. Femoral components with NSAs of 130° or 135° may historically have been based on X-ray misinterpretation. This work demonstrates that 2D to 3D reconstruction of the proximal femur in pre-op planning is a challenge

Introduction:. External rotation (ER) of the shoulder is a commonly used clinical measurement to assess the glenohumeral joint; however, the position in which these measurements are obtained varies between clinicians. The purpose of this study was to compare the following: ER in the upright & supine positions, motion capture & goniometric values of ER, active & passive ER, ER in the right & left shoulders, and ER in male & female subjects. Methods:. Eighteen subjects (mean age 25.4 yrs) with ‘normal’ shoulders (by screening questionnaire) were enrolled in the study and subject to triplicate measurements of active and passive ER of both shoulders with a goniometer and a 12 camera, high speed optical motion analysis system in both the upright and supine positions. ANOVA was used to compare variables and linear regression used to correlate the goniometer & optical motion capture measurements. Results:. On average, shoulder ER in the supine position was 10.0° greater than in the upright position (p < 0.001) using the motion capture data and 5.8° greater using the goniometer (p = 0.025). There was a strong correlation between the goniometer and optical motion capture measurements with an R. 2. value of 0.6573 (p = 2.39E-13); on average, the goniometer readings were 11.0° greater than the corresponding optical measurements. External rotation of the right shoulder was 7.2° greater than the left using the optical measurements (p = 0.02) and 4.4° greater with the goniometer (p = 0.039). In addition, females did have significantly greater external rotation than males using the optical measurements (p < 0.001), averaging 16.7° more external rotation; findings were similar for the goniometric measurements with 18.5° greater average external rotation seen in female subjects (p < 0.001). There was no significant difference between measured active and passive external rotation (p = 0.589). Conclusion:. Significant differences do exist between measured values of external rotation depending on the position of measurement (upright vs supine), hand dominance, and gender. It does not appear that there is a difference between active and passive external rotation. Our recommendations are for the musculoskeletal clinician to be meticulous when documenting the position of measured external rotation, as values vary depending on the position of measurement. One should also be cautious of comparing external rotation of one shoulder to the contralateral side, as well as comparing values between genders, as these measurements appear to be different as well

Introduction. While shoulder elevation can be reliably restored following reverse total shoulder arthroplasty (RTSA), patients may experience a loss of internal and external rotation. Several recent studies have investigated scapular notching and have made suggestions regarding glenosphere placement in order to minimize its occurrence. However, very few studies have looked at how changes in glenosphere placement in RTSA affect internal and external rotation. The purpose of this study was to determine the effect of glenosphere position on internal and external rotation range of motion at various degrees of scaption following RTSA. We hypothesized that alteration in glenosphere position will affect the amount of impingement-free internal and external rotation. Methods. CT scans of the scapula and humerus were obtained from seven cadaver specimens and 3-Dimensional (3D) reconstructions were created. A corresponding 3D RTSA model was created by laser scanning the baseplate, glenosphere, humeral stem and bearing. The RTSA models were then virtually implanted into each specimen. The glenosphere position was determined in relation to the neutral position in 6 different settings: Medialization (5 mm), lateralization (10 mm), superior translation (6mm), inferior translation (6 mm), superior tilt (20°), and inferior tilt (15° and 30°). The humerus in each virtual model was allowed to freely rotate at a fixed scaption angle until encountering bone-bone or bone-implant impingement (180 degrees of limitation). Each model was tested at 0, 20, 40, and 60 degrees of scaption and the impingement-free internal and external rotation range of motion for each scaption angle was recorded. Results. At 0Ëš scaption, only inferior translation, lateralization, and inferior tilt allowed any impingement-free motion in IR and ER. At mid ranges of scaption (20Ëš and 40Ëš) a predictable pattern was seen in which increased lateralization and inferior translation resulted in improved rotation. Supraphysiologic motion (>90Ëš rotation) was seen consistently at 60Ëš of scaption in internal rotation. Both superior and inferior tilt positions resulted in increased ROM in the mid-range of scaption. Acromial impingement was seen when the glenosphere was medialized, superiorly translated and with a superior tilt. Superior translation (6 mm) resulted in no rotation at 0 and 20 degrees of scaption (both IR and ER). Figure 1 and 2: Represents the amount of internal (fig. 1) and external rotation (fig. 2) range of motion measured to bony impingement. 180 degrees was set as the physiologic limit for all measurements. Conclusion. Glenosphere position significantly affected humeral internal and external rotation after Reverse Total Shoulder Arthroplasty in our computer model. Inferior translation (6 mm) or lateralization (10 mm) appears to have the most beneficial effects to internal and external rotation of the shoulder. Inferior tilt (15° and 30°) of the glenosphere also improved overall arc of motion in IR and ER when compared to superior tilt and neutral positions. Superior translation (6 mm) and medialization (5 mm) of the glenosphere caused marked limitations in internal and external rotation due to scapular notching and acromial impingement

External rotation of the shoulder is commonly measured in two ways, with the arm adducted or with the arm abducted to 90°. The measurement forms an important part of the assessment of shoulder function, but has been shown to be unreliable. Following the observation that, with the arm adducted, the range of external rotation alters according to the exact position of the arm in the sagittal plane, we conducted a study to quantify the effect on the range of external rotation of a small increment in forward flexion (15°). With the arm first in a vertical position and then in 15° of forward flexion, external rotation was measured in 40 asymptomatic and 20 ‘frozen’ shoulders. With forward flexion, the range of external rotation decreased by a mean of 16.9° in the asymptomatic and 13.5° in the ‘frozen’ shoulders. We postulate that some of the variation is a function of scapular positioning. With arm flexion, the scapula protracts, resulting in alteration in glenoid version. However, some difference is due also to alteration in soft tissue tension in the two arm positions. The sagittal position of the arm affects the range of external rotation of the adducted shoulder. This variation in measurement may affect the scores of certain outcome measures

Patients using a neutral rotation brace post proximal humerus fracture fixation have improved functional outcome and external rotation of the shoulder compared to patients using a standard polysling. Patients who have proximal humerus fracture fixation with extramedullary plates and screws have a risk of reduced range of movement especially external rotation. Gerber et al showed that the average external rotation after fixation of proximal humeral fractures was 39 degrees in their patient cohort compared to a normal range of 80–100 degrees. This can lead to reduced function and poor patient related outcomes. Geiger et al showed that in a cohort of 28 patients, poor functional outcome was noted in 39.3% with an average Constant-Murley Score of 57.9. Current practice is to utilise a polysling holding the shoulder in internal rotation post-shoulder fixation. Patients usually wear the sling for up to 6 weeks. We believe that this increases the risk of adhesion formation with the shoulder in internal rotation in the shoulder joint. Therefore this can cause loss of external rotation in the shoulder joint. We believe that holding the shoulder in a neutral alignment, with a neutral rotation brace post-fixation, will enable an increased rate of external rotation post-operatively thus improving external rotation and functional outcome. There is currently no literature comparing the different slings used post-operatively and we believe that this study would be the first of its kind. It would have a substantial change in the way clinicians manage proximal humeral fractures and will potentially reduce the numbers of re-operations to divide adhesions or perform capsular releases. Secondary benefits include a potential earlier return to full function and work and improved patient satisfaction. Study proposal: Prospective Randomised Controlled Trial of the neutral rotation brace compared to the standard, currently used, polysling post proximal humerus fracture fixation. No blinding of either participants or clinicians. Three surgeons utilising similar fixation techniques via the deltopectoral approach and using Philos plate fixation (Synthes Ltd.). Standardised post-operative rehabilitation protocol for all patients. Follow up: clinical review and postal outcomes for 1 year. Primary outcomes: Post operative functional outcome scores (Oxford, DASH, EQL) obtained at 6 weeks, 9 weeks, 3 months and 1 year). These will be compared to scores taken pre-operatively. Secondary outcomes: Clinical review at 6 weeks, 3 months and 1 year with range of movement measurements. Radiographs also taken at 6 weeks and 3 months to assess union. Patient questionnaire at 1 year (with outcome scores) assessing patient return to work, complications and patient satisfaction. Inclusion criteria: Proximal humeral fractures requiring operative intervention with extramedullary plate fixation (i.e. fractures displaced by 1cm and/or angulated by 45 degrees or more). Age>18. Exclusion Criteria: Patients having intra-operative findings of complete Pectoralis major rupture or if operative exposure requires complete Pectoralis major tenotomy. (These patients need to be held in internal rotation with a standard polysling to allow healing of the Pectoralis major tendon)

Background. Scapular notching is a complication after reverse shoulder arthroplasty with a high incidence up to 100%. Its clinical relevance remains uncertain; however, some studies have reported that scapular notching is associated with an inferior clinical outcome. There have been no published articles that studied positional relationship between the scapular neck and polyethylene insert in vivo. The purpose of this study was to measure the distance between the scapular neck and polyethylene insert in shoulders with Grammont type reverse shoulder arthroplasty during active external rotation at the side. Methods. Eighteen shoulders with Grammont type prosthesis (Aequalis Reverse, Tornier) were enrolled in this study. There were 13 males and 5 female, and the mean age at surgery was 74 years (range, 63–91). All shoulders used a glenosphere with 36mm diameter, and retroversion of the humeral implant was 10°in 4 shoulders, 15°in 3 shoulders, and 20°in 11 shoulders. Fluoroscopic images were recorded during active external rotation at the side from maximum internal to external rotation at the mean of 14 months (range, 7–24) after surgery. The patients also underwent CT scans, and three-dimensional glenosphere models with screws and scapula neck models were created from CT images. CT-derived models of the glenosphere and computer-aided design humeral implant models were matched with the silhouette of the implants in the fluoroscopic images using model-image registration techniques (Figure 1). Based on the calculated kinematics of the implants, the closest distance between the scapular neck and polyethylene insert was computed using the scapular model and computer-aided design insert models (Figure 2). The distance was computed at each 5° increment of glenohumeral internal/external rotation, and the data from 20°internal rotation to 40°external rotation were used for analyses. One-way repeated-measures analysis of variance was used to examine the change of the distance during the activity, and the level of significance was set at P < 0.05. Results. The mean glenohumeral abduction during the activity was 17°-22°. The mean distance between the neck and insert was approximately 1mm throughout the activity (Figure 3). The distance tended to become smaller with the arm externally rotated, but the change was not significant. Discussion. The reported incidence of scapular notching after Grammont type reverse shoulder arthroplasty is generally higher than the newer design prosthesis with the lateralized center of rotation. This may be associated with the design of the prosthesis, and the results of this study that the distance between the neck and insert was approximately 1mm throughout active external rotation at the side will support the high incidence of notching. We may need to analyze the distance with the newer design reverse shoulder prosthesis to prove the architectural advantage of the newer systems. Conclusion. The distance between the scapular neck and polyethylene insert was approximately 1mm throughout active external rotation activity in shoulders with Grammont type prosthesis

Introduction: Preliminary data suggest that immobilization in external rotation may be effective in lowering the incidence of recurrence after first traumatic shoulder dislocation, with a zero reoccurrence rate reported at 15 months follow-up. The purpose of the present study was to ascertain whether this method could lower the incidence of recurrent dislocation in a young, very physically active population. Methods: In an IRB approved prospective study, young males who sustained first traumatic shoulder dislocation were randomized to be treated for four weeks either using a traditional internal rotation brace or a new device which immobilizes the shoulder at 15 to 20 degrees of external rotation. Subjects were then treated according to a standard physical therapy protocol. Follow-up was done at five time points in the first year post dislocation. Subjects with clinically stable shoulders resumed full activity after three months. Differences in outcome were assessed by the chi square test. Results: Thirty nine subjects participated in the study. Thirty of them were soldiers. Twenty four subjects were treated with external rotation braces. At follow-up of between 4 to 28 months, a new dislocation was documented in 8 of the 24 subjects immobilized in external rotation (33%) and in 5 of the 15 subjects immobilized in internal rotation (33 %). No statistical difference (p=1.0) was found between the instability rates of the two treatment groups. Discussion: The present study indicates that even in a short-term follow-up the technique of immobilizing a first dislocation in external rotation was not effective in lowering the incidence of recurrent shoulder dislocations in a young, physically active population

Reverse total shoulder arthroplasty (RTSA) was designed to treat the cuff-deficient shoulder with arthritis and irreparable rotator cuff tears of the supraspinatus and infraspinatus tendons. The results of RTSA in this patient population have been very good and reliable in the majority of cases. However, it has also been reported that patients whose rotator cuff tear involves the supraspinatus, infraspinatus and teres minor and who demonstrate a ‘horn-blower's sign’ do very poorly if a muscle transfer is not performed to improve external rotation in these shoulders in abduction. The loss of the teres minor in these patients results in grave difficulty for the patient attempting to perform their activities of daily living even if they can obtain reasonable good forward flexion. The muscle transfer that is most commonly used for these select patients is a latissmus dorsi tendon transfer in conjunction with RTSA. The purpose of this talk is to review the pathology of this problem and review the technique for its surgical treatment

Introduction. The effect of each step of medial soft tissue releases on the external rotation angle of the femoral component was assessed during posterior stabilized total knee arthroplasty (PS-TKA) with modified gap control technique. Methods. Consecutive 840 knees were assessed. During PS-TKA, medial soft tissue release was done to obtain rectangular gap in extension using tensors/balancers. The deep fiber of medial collateral ligament (MCL) was released in all cases. No more release was done in 464 knees. Only anterior fiber of superficial MCL was released in 49 knees, and only posterior fiber of superficial MCL was released in 129 knees. Both fibers were released in 169 knees. Additional pes anserinus was released in 29 knees. Rotation angle of the femoral component was decided based on the flexion gap angle. The angle was compared among the five groups. Results. The average external rotation angle of the femoral component was 4.8°, 5.3°, 4.6°, 4.3°, 4.1°, respectively. The external rotation angle in knees after release of superficial MCL fibers and more was statistically significantly smaller compared to that in knees without release (P<0.001). Conclusion. Releases of MCL superficial fibers and more in order to obtain soft tissue balancing in extension significantly widened the medial joint gap in flexion and reduced external rotation angle of the femoral component

Patello-femoral tracking and polyethylene wear are strongly dependent on rotational alignment of the components in total knee arthroplasty. In the current literature four methods to obtain correct axial femoral alignment are reported: the transepicondylar axis method, Whiteside’s method, the tibial axis method and 3° external rotation of posterior condyles method. Because of its simplicity the last of these is the most popular method used at present. But it is also the most accurate? The purpose of this study was to investigate the accuracy of the 3° external rotation method, comparing it to the transepicondylar axis and the White-side’s A-P line. We performed a CT scan examination of the hip and the knee of 40 patients scheduled to undergo a total knee arthroplasty. Seven cases of valgus deformity were excluded from the study, leaving 34 cases. The mean age was 72.4 and the left knee was involved in 23 cases. The mean height was 159 cm and the mean weight was 76.6 kg. The mean varus deformity was 14° (min 5° – max 30°). CT scan was conducted using a Picker PQCT machine. Two axial images were obtained in all the patients: one of the femoral neck and one of the knee with good visualisation of the posterior aspect of the condyles of the femur and epicondyles. We measured the following angles: the femoral anteversion angle (between the femoral neck line and the posterior condylar line), the posterior condylar angle (between the posterior condylar line and the transepicondylar axis) and the Whiteside’s angle (between the posterior condylar line and the perpendicular line to the White-side’s A-P line). The mean femoral anteversion angle was 5.5°± 13.7° (min -24°; max 33°). The mean posterior condylar angle was 6.1°± 2.5° (min 1°; max 14°). In 20 cases (60.6%) the posterior condylar angle was greater than 5°. The mean Whiteside’s angle was 6°±3.5° (min 1°; max 16.5°). In 17 cases (51.5%) it was greater than 5°. Both the posterior condylar angle and the White-side’s angle showed average values, which doubled the 3° proposed as standard for external rotational alignment of the femoral component, with maximum values of 14° and 16.5° respectively. More than 50% of the cases showed a posterior condylar angle grater than 5°. The two methods (transepicondylar and Whiteside’s line) are complementary. The posterior condylar axis and the Whiteside’s line were not altered by severe varus deformity or femoral neck retro- or anteversion. The 3° external rotation of the posterior condyle line is not recommended as a standard procedure to determine the degree of external rotation of the femoral component in total knee arthroplasty

Introduction. Patellofemoral (PF) complications are among the most frequently observed adverse events after total knee arthroplasty (TKA). It has been reported that PF complications after TKA include decreasing knee range of motion, anterior knee pain, quadriceps and patellar-tendon rupture, patellar subluxation, and partial abrasion and loosening of the patellar component. Although recent improvements in surgical technique and prosthetic design have decreased these complications, the percentage of patients who have a revision TKA for PF complications still ranged up to 6.6% to 12%. For the present study, we hypothesized that the alignment of the femoral component is correlated with PF contact stress. The purpose of this study was to investigate the relationship between femoral component alignment and PF contact stress in vivo, using a pressure sensor in patients who had favorable extension-flexion gap balance during TKA. Methods. Thirty knees with medial compartment osteoarthritis that underwent posterior stabilized mobile-bearing TKA using identical prostheses (PFC Sigma RPF; Depuy, Warsaw, IN, USA) by a single surgeon (TM) with modified gap technique under a computed tomography (CT)-based navigation system (Vector Vision 1.61; Brain Lab, Heimstetten, Germany) were evaluated. PF contact stress was measured intraoperatively and compared with the alignment of the femoral component including intraoperative navigation data concerning medial shift of the patella and lateral tilt of the patella, postoperative coronal femoral component angle (alpha angle), postoperative sagittal femoral component angle (gamma angle), postoperative condylar twist angle (CTA), postoperative lateral condylar lift-off angle, and postoperative mechanical femoral component angle (mFCA). In addition, postoperative Insall-Salvati ratio (I-S ratio) was measured by dividing the length of patellar tendon by the greatest diagonal length of the patella. Results. Maximum PF stress was 2.4 ± 1.9 MPa, medial shift of the patella was 2.6 ± 1.5 mm, and lateral tilt of the patella was 8.5 ± 4.2 degrees. The PF contact stress was not correlated sagittal and coronal alignment of the femoral component and patella tracking, whereas rotational alignment of the femoral component was negatively correlated with the PF contact stress (r = −0.718, p < 0.01). Discussion and conclusion. Multiple regression analysis shows that PF contact stress correlates with CTA, I-S ratio positively correlates with PF contact stress in Spearman correlation analysis. The results of the present study showed a negative correlation between maximum stress in the PF joint and CTA. It has been reported that excessive external rotation increases the medial flexion gap, leading to symptomatic flexion instability of the femoral component. In addition, external rotation of the femoral component can cause relative medialization of the trochlear groove during flexion, resulting in anterior knee pain. Therefore, we should carefully decide the proper rotational alignment of the femoral component. It has been reported that PF contact stress in a normal knee was from 2.1 to 2.9 MPa in a cadaveric study. In the present study, patients with rotational alignment of the femoral component after TKA between 1.2° and 2.2° internally rotated from CEA had PF contact stress in this normal range

Placement of total knee arthroplasty components is typically controlled via resections that reference bony landmarks. For example, external rotation of the femoral component can be pre-determined by referencing the posterior condyles or the epicondylar axis. Such approaches exclude consideration of any potential effect of the collateral ligaments before resection are made. In addition, bone referencing instrumentation usually limits femoral component placement to discrete values of external rotation such as 3° or 5°. The purpose of the present study was to determine external rotation of the femoral component following use of a novel ligament balancing approach and to assess the accuracy of balancing the flexion and extension gaps with this ligament balancing system. One hundred twenty knees in 110 patients were consecutively enrolled by a single surgeon using the same implant across subjects. All patients underwent arthroplasty that set external rotation of the femoral component based upon use of a novel ligament balancing system. Following ligament tensioning/balancing, the femur was prepared. Thicknesses of the medial and lateral posterior condylar resections were measured and the difference between the two measurements was calculated. When placed into relation with the line formed by the distance between the midpoints of the distal condyles (reference line), the difference in the condylar resections gives the height of a right triangle. The arc tangent function was then used to calculate the resultant angle (external rotation) formed from the reference line and the hypotenuse. The average, range and standard deviation of the external rotation values was found. External rotation averaged 6.9° (+/−2.8°) and ranged from 0.6° to 12.8°. Fifty-four percent of femoral components were sized 3, 4 or 5. The external rotation values in this study were 4° and 2° larger, respectively, than the typical 3° and 5° discrete values that are common to measured resection systems. External rotation values are higher on average, when ligament tensioning/balancing is employed with this novel system compared to measured resection systems. Also, the standard deviation and range suggests that true femoral rotation varies greatly between patients. This finding suggests that limiting the surgeon to discrete rotation values may be at odds with where the femur “desires” to be, given soft tissue considerations for each patient. Future work includes determining whether there is a functional difference between measured resection and this ligament tensioning/balancing approach. The accuracy of the ligament balancing system was assessed by applying equal tension on the ligaments using a tensioning bolt and torque wrench in flexion and extension after the bone resections had been made. The resulting flexion and extension gaps were then measured to determine rectangular shape and equality of the gaps. Rectangular flexion and extension gaps were obtained within 0.5 mm in all cases. Equality of the flexion and extension gaps was also obtained within 0.5 mm 100% of the time. To the best of our knowledge, this system and technique has produced better accuracy balancing the flexion and extension gaps in total knee arthroplasty than has previous been reported

INTRODUCTION. Use of a novel ligament gap balancing instrumentation system in total knee arthroplasty resulted in femoral component external rotation values which were higher on average, compared to measured resection systems. In one hundred twenty knees in 110 patients the external rotation averaged 6.9 degrees (+/− 2.8) and ranged from 0.6 to 12.8 degrees. The external rotation values in this study were 4° and 2° larger, respectively, than the typical 3° and 5° discrete values that are common to measured resection systems. The purpose of the present study was to determine the effect of these greater external rotation values for the femoral component on patellar tracking and flexion instability. METHODS. One hundred twenty knees in 110 patients were consecutively enrolled by a single surgeon using the same implant across subjects. All patients underwent arthroplasty with tibial resection first and that set external rotation of the femoral component based upon use of a ligament gap balancing system. Following ligament tensioning/balancing, the femur was prepared. The accuracy of the ligament balancing system was assessed by reapplying equal tension to the ligaments using a tensioning bolt and torque wrench in flexion and extension after the bone resections had been made. The resulting flexion and extension gaps were then measured to determine rectangular shape and equality of the gaps. Postoperative Merchant views were obtained on all of the patients and patellar tracking was assessed and compared to 120 consecutive total knee arthroplasties previously performed by the same surgeon with the same implant using a measured resection system. RESULTS. Rectangular flexion and extension gaps were obtained within +/− 0.5mm in all cases. Equality of the flexion and extension gaps was also obtained within +/− 0.5mm in all cases. Merchant views of the total knee arthroplasties showed central patellar tracking with no tilt or subluxation in 90% of the ligament gap balanced knees and 74% of the measured resection knees. DISCUSSION AND CONCLUSION. External rotation values are higher on average, when ligament tensioning/balancing is employed with this novel system compared to measured resection systems. In this study this resulted in consistent matching of the flexion gap to the extension gap and better patellar tracking. These findings suggest that limiting the surgeon to discrete rotation values may be at odds with where the femur “desires” to be, given soft tissue considerations for each patient

Purpose of the study: The aim of this study was to analyze rotation of the normal and prosthetic distal femur as well as the spaces from 90 to 130 degrees flexion. Material and methods: Torsion scans were obtained preoperatively and postoperatively for 44 total knee prostheses. The difference in femoral torsion between the pre- and postoperative image was used to assess the rotation in which the femoral component was implanted. The prostheses were divided into two groups: group I when the femoral implant was implanted with external rotation of more than 5°; group II when the femoral implant was implanted with external rotation less than 5°. A preoperative stress scan was obtained in 20 patients then repeated during the year following implantation. Stress images with knee flexion at angles from 90° to 130° were obtained. The patient was installed in the ventral supine position. 8mm scan slices were centered on the lower end of the femur, ten 50ms images were acquired during flexion movement from 90° to 130°. This enabled determination of the knee flexion axis preoperatively and postoperatively, to measure the variation in the epicondylar axis compared with the mechanical axis of the tibia between 90° and 130° flexion and finally to deduct change in the femorotibial space in flexion from 90° to 130°. Results: The 18 total knee prostheses with a femoral component implanted with external rotation greater than 5° (group I) showed significantly greater range of flexion (p< 0.05) (mean 120°, range 110°–130°) than the 26 prostheses in group II with a femoral component implanted in external rotation less than 5° (mean 100°, range 80°–115°. For the 20 knees with stress scans, the preoperative images showed an epicondylar axis about 5° fro the mechanical axis of the tibia when the knee flexed in the 90°–130° range. After surgery, the stress scans showed that this epicondylar axis of rotation of the prosthesis-bearing knees occurred especially for knees with a wide range of flexion. The 20 knees with flexion limited to 100° did not present an epicondylar rotation axis compared with the mechanical axis of the tibia. The 15 knees with 125° flexion or more had an epicondylar axis of rotation after 90° flexion. Rotation of the epicondylar axis in relation to the mechanical axis of the tibia between 90° and 130° flexion was the consequence of a femorotibial space which changed in the medial and laeral femorotibial compartments between 90° and 130° flexion: after 90° flexion, the medial femorotibial space decreased and the lateral femorotibial space increased. This explains why movement from 90° flexion to 130° flexion was facilitated by placing the femoral piece in external rotation. Discussion: Search for ligament balance for knee flexion above 90° is logical only if the goal is to obtain knee stability in extension and flexion at 90°. It is probably no rational if the goal is to allow the knee to reach flexion in the 120°–130° range. Ligament balance in flexion above 90° is important and should be maintained up through 130° flexion. The other solution is to empirically increase external rotation of the femoral component a few degrees in order to allow greater range of flexion

The traditional treatment for a primary anterior shoulder dislocation has been immobilisation in a sling with the arm in adduction and internal rotation. The recurrence rates after the initial traumatic event range from 20% to 94%. However, recent results have suggested that recurrent instability after primary shoulder dislocation may be reduced with immobilisation in external rotation. Since then, controversy exists regarding the position of immobilisation following these injuries. The objective of the present study was to compare immobilisation in internal and external rotation after a primary anterior shoulder dislocation. Fifty patients presenting to our fracture clinic with a primary traumatic anterior dislocation of the shoulder were randomly assigned to treatment with immobilisation in either internal rotation (IR; 25 patients) or external rotation (ER; 25 patients) for three weeks. In addition of a two-years clinical follow-up, patients underwent a magnetic resonance imaging (MRI) of the shoulder with intra-articular contrast within four days following the traumatic event, and then at three months of follow-up. The primary outcome was a recurrent dislocation within 24 months of follow-up. The secondary outcome was the healing rate of the labral lesion seen on MRI (if present) within each immobilisation group. The follow-up rate after two years was 92% (23 of 25) in the IR group and 96% (24 of 25) in the ER group. The recurrence rate in the IR group (11 of 23; 47.8%) was higher than that in the ER group (7 of 24; 29.2%) but the difference did not reach statistical significance (p=0.188). However, in the subgroup of patients aged 20–40 years, the recurrence rate was significantly lower in the ER group (3 of 17; 6.4%) than that in the IR group (9 of 18; 50%, p<0,01). In the subgroup of patients with a labral lesion present on the initial MRI, the healing rate of the lesion was 46.2% (6 of 13) in the IR group and 60% (6 of 10) in the ER group (p=0.680). Overall, the recurrence rate among those who showed healing of the labrum (regardless of the immobilisation group) was 8.3% (1 of 12), but patients who did not healed their labrum had a recurrence rate of 45.5% (5 of 11; p=0.069). This study suggests that immobilisation in ER reduces the risk of recurrence after a primary anterior shoulder dislocation in patients aged between 20 and 40 years. At two years follow-up, the recurrence rate is lower in patients who demonstrated a healed labrum at three months, regardless of the position of immobilisation. Future studies are required in order to identify factors that can improve healing of the damaged labrum following a traumatic dislocation of the shoulder

Purpose of the study: A stiff shoulder in internal rotation is a classical complication of obstetrical injury to the brachial plexus. The condition generally associates glenohumeral dysplasia. In 2003, Pearl proposed arthroscopic release of the shoulder, with or without latissimus dorsi transfer as an alternative to an open procedure. We report a series of 13 patients who underwent this procedure. Material and method: From 2004 to 2007, 13 children aged 1 to 11 years (range 3.5) underwent surgery. The procedure was an arthroscopic tenotomy of the intra-articular portion of the subscapularis associated with release of the anterior capsuloligament structures without tendon transfer. A thoracobrachial resin cast maintained the shoulder in maximal external rotation for six weeks. The functional outcome was assessed on the basis of the passive and active range of motion and the Mallet score. Pre and postoperative MRI was used to assess glenohumeral dysplasia and check its correction. Results: Mean follow-up was 23 months (range 5–40). There were no complications. Mean immediate postoperative gain was 53 (range 30–70) for external rotation (RE1). On average, passive RE1 improved from −5.4 to +57.7. Eight patients (61%) recovered active external rotation (57.5 on average). Mean active abduction improved from 45.8 to 56.5. Active internal rotation declined in 38% of the shoulders. The Mallet score improved in 69% of the shoulders. The best results were observed for children aged less than 4 years. There was one failure, related to major dyplasia which could not be reduced with an open procedure. Correction of the glenohumeral dysplasia was noted on 7 of the 9 MRI performed and the retroversion angle of the glenoid improved from −28.2 to −25.6, on average. Discussion: Open techniques are aggressive and only variably effective. A majority of our patients (8/13) achieved improved passive and active RE1 solely with the arthroscopic procedure. Correction of the glenohumeral dysplasia with growth appears to correspond to the clinical improvement but further follow-up is needed. Conclusion: Our results are comparable with those reported by Pearl. This is a minimally invasive easy-to-perform technique. For children aged less than 4 years, systematic tendon transfer does not appear to be necessary