Aims. This study compared patients who underwent arthroscopic repair of large to massive rotator cuff tears (LMRCTs) with isolated incomplete repair of the tear and patients with incomplete repair with biceps tendon augmentation. We aimed to evaluate the additional benefit on clinical outcomes and the capacity to lower the re-tear rate. Methods. We retrospectively reviewed 1,115 patients who underwent arthroscopic rotator cuff repair for full-thickness tears between October 2011 and May 2019. From this series, we identified 77 patients (28 male, 49 female) with a mean age of 64.1 years (50 to 80). Patients were classified into groups A (n = 47 incomplete) and B (n = 30 with biceps augmentation) according to the nature of their reconstruction. Clinical scores were checked preoperatively and at six months, one year, and two years postoperatively. In preoperative MRI, we measured the tear size, the degree of fatty infiltration, and muscle volume ratio of the supraspinatus. In postoperative MRI, the integrity of the repaired rotator cuff tendon was assessed using the Sugaya classification. Tendon thickness at the footprint was evaluated on T2-weighted oblique coronal view. Results. There were no significant differences in the initial preoperative demographic characteristics. In both groups, there were significant improvements in postoperative clinical scores (p < 0.001). However, most clinical outcomes, including range of motion measurements (forward elevation, external rotation, internal rotation, and abduction), showed no differences between the pre- and postoperative values. Comparing the postoperative outcomes of both groups, no further improvement from biceps augmentation was found. Group B, although not reaching statistical significance, had more re-tears than group A (30% vs 15%; p = 0.117). Conclusion. In LMRCTs, biceps augmentation provided no significant improvement of an incomplete repair. Therefore, biceps augmentation is not recommended in the treatment of LMRCTs. Cite this article: Bone Joint J 2022;104-B(11):1234–1241

Aims. To develop and internally validate a preoperative clinical prediction model for acute adjacent vertebral fracture (AVF) after vertebral augmentation to support preoperative decision-making, named the after vertebral augmentation (AVA) score. Methods. In this prognostic study, a multicentre, retrospective single-level vertebral augmentation cohort of 377 patients from six Japanese hospitals was used to derive an AVF prediction model. Backward stepwise selection (p < 0.05) was used to select preoperative clinical and imaging predictors for acute AVF after vertebral augmentation for up to one month, from 14 predictors. We assigned a score to each selected variable based on the regression coefficient and developed the AVA scoring system. We evaluated sensitivity and specificity for each cut-off, area under the curve (AUC), and calibration as diagnostic performance. Internal validation was conducted using bootstrapping to correct the optimism. Results. Of the 377 patients used for model derivation, 58 (15%) had an acute AVF postoperatively. The following preoperative measures on multivariable analysis were summarized in the five-point AVA score: intravertebral instability (≥ 5 mm), focal kyphosis (≥ 10°), duration of symptoms (≥ 30 days), intravertebral cleft, and previous history of vertebral fracture. Internal validation showed a mean optimism of 0.019 with a corrected AUC of 0.77. A cut-off of ≤ one point was chosen to classify a low risk of AVF, for which only four of 137 patients (3%) had AVF with 92.5% sensitivity and 45.6% specificity. A cut-off of ≥ four points was chosen to classify a high risk of AVF, for which 22 of 38 (58%) had AVF with 41.5% sensitivity and 94.5% specificity. Conclusion. In this study, the AVA score was found to be a simple preoperative method for the identification of patients at low and high risk of postoperative acute AVF. This model could be applied to individual patients and could aid in the decision-making before vertebral augmentation. Cite this article: Bone Joint J 2022;104-B(1):97–102

Abstract. Introduction. Augmentation of meniscus repairs with fibrin clot may enhance the healing capacity. Pulling the clot into the tear with a suture ensures that it stays in position. This paper aims to assess the outcome of this technique. Methods. 52 patients over 4 years undergoing suture repair of a meniscus tear with blood clot augmentation were collected from a prospective database. Follow up included outcome scores and a questionnaire. Failure was defined as pain or further surgery secondary to meniscal pathology. Results. There were 32 males and 20 females, mean age of 35 (14–70). The medial meniscus was repaired in 32 knees and the lateral in 20. Complete radial tears were the most common type. Only 2% of tears were in the red-red zone. Follow-up ranged from 12 months to 7 years. Only 1 patient is known to have come to subsequent arthroscopy. Lysholm scores improved from 53.97 (SD 18.14) to 92.08 (SD 8.97), Oxford Knee Scores from 29.84 (SD 9.65) to 45.79 (SD 2.66), KOOS pain scores from 61.49 (SD 22.76) to 93.54 (SD 8.06) and Tegner scores from 4.56 (SD 3.35) to 6.05 (SD 2.41). Conclusions. Pulling a fibrin blood clot into a meniscus tear with a suture ensures that the clot remains in place while the meniscus is repaired. Patients have shown excellent outcomes with 98% survivorship at 45 months. This is a reliable technique for augmenting meniscus repairs especially for tears which otherwise may not have been repaired

This study was proposed to evaluate the efficacy of fibrin clot augmentation in meniscal tear using inside-out meniscal repair. A total of 35 patients with meniscus tears were operated on with inside-out meniscus repair and fibrin clot augmentation. Patients were evaluated preoperatively and postoperatively with clinical criteria, Lysholm knee scoring system, and MRI. Out of the total 35 cases, 5 cases were lost to follow up. Clinical improvement was observed in 29 out of 30 patients (96.6%). The mean Lysholm score improved significantly from 67.63 ± 6.55 points preoperatively to 92.0 ± 2.9 points postoperatively (P < 0.05) in 2 years follow-up. Follow-up MRI in all patients revealed complete healing except in 1 case where the patient presented with recurrence of symptoms such as pain and locking which resolved with partial meniscectomy. Paraesthesia in the anterior part of the knee was observed in 2 cases. (6.6%). We conclude that fibrin clot augmentation is a good cost-effective modality of treatment for repairable meniscus tears to preserve the meniscus and decrease the point contact pressure on the condyles which may prevent the early occurrence of osteoarthritis

We report the clinical outcome and findings at second-look arthroscopy of 216 patients (mean age 25 years (11 to 58)) who underwent anterior cruciate ligament (ACL) reconstruction or augmentation. There were 73 single-bundle ACL augmentations (44 female, 29 male), 82 double-bundle ACL reconstructions (35 female, 47 male), and 61 single-bundle ACL reconstructions (34 female, 27 male). In 94 of the 216 patients, proprioceptive function of the knee was evaluated before and 12 months after surgery using the threshold to detect passive motion test. Second-look arthroscopy showed significantly better synovial coverage of the graft in the augmentation group (good: 60 (82%), fair: 10 (14%), poor: 3 (4%)) than in the other groups (p = 0.039). The mean side-to-side difference measured with a KT-2000 arthrometer was 0.4 mm (-3.3 to 2.9) in the augmentation group, 0.9 mm (-3.2 to 3.5) in the double-bundle group, and 1.3 mm (-2.7 to 3.9) in the single-bundle group: the result differed significantly between the augmentation and single-bundle groups (p = 0 .013). No significant difference in the Lysholm score or pivot-shift test was seen between the three groups (p = 0.09 and 0.65, respectively). In patients with good synovial coverage, three of the four measurements used revealed significant improvement in proprioceptive function (p = 0.177, 0.020, 0.034, and 0.026). We conclude that ACL augmentation is a reasonable treatment option for patients with favourable ACL remnants. Cite this article: Bone Joint J 2014;96-B:1325–32

The December 2023 Research Roundup. 360. looks at: Tissue integration and chondroprotective potential of acetabular labral augmentation with autograft tendon: study of a porcine model; The Irish National Orthopaedic Register under cyberattack: what happened, and what were the consequences?; An overview of machine learning in orthopaedic surgery: an educational paper; Beware of the fungus…; New evidence for COVID-19 in patients undergoing joint replacement surgery

Rotator cuff tears are common in middle-aged and elderly patients. Despite advances in the surgical repair of rotator cuff tears, the rates of recurrent tear remain high. This may be due to the complexity of the tendons of the rotator cuff, which contributes to an inherently hostile healing environment. During the past 20 years, there has been an increased interest in the use of biologics to complement the healing environment in the shoulder, in order to improve rotator cuff healing and reduce the rate of recurrent tears. The aim of this review is to provide a summary of the current evidence for the use of forms of biological augmentation when repairing rotator cuff tears. Cite this article: Bone Joint J 2024;106-B(9):978–985

Gluteal Tendinopathy is a poorly understood condition that predominantly affects post-menopausal women. It causes lateral hip pain, worse when lying on the affected side or when walking up a hill or stairs. It has been labelled ˜Greater Trochanteric Pain Syndrome” a name that recognises the lack of understanding of the condition. Surgical reconstruction of the gluteal cuff is well established and has been undertaken numerous times over the last 16 years by the senior author (AJL). However, the quality of collagen in the tendons can be very poor and this leads to compromised results. We present the results of gluteal cuff reconstruction combined with augmentation using a bioinductive implant. 14 patients (11 female, 3 male; mean age 74.2 ± 6.3 years) with significant symptoms secondary to gluteal tendinopathy that had failed conservative treatment (ultrasound guided injection and structured physiotherapy) underwent surgical reconstruction by the senior author using an open approach. In all cases the iliotibial band was lengthened and the trochanteric bursa excised. The gluteal cuff was reattached using Healicoil anchors (3–5×4.75mm anchors; single anchors but double row repair) and then augmented using a Regeneten patch. Patients were mobilised fully weight bearing post-operatively but were asked to use crutches until they were no longer limping. All had structured post-surgery rehabilitation courtesy of trained physiotherapists. There were no post-operative complications and all patients reported an improvement in pain levels (Visual Analogue Scale 7.8 pre-op; 2.6 post-op) and functional levels (UCLA Activity Score 3.5 pre-op; 7.1 post-op) at 6 months post surgery. Surgery for gluteal tendinopathy produces good outcomes and the use of Regeneten as an augment for poor quality collagen is seemingly a safe, helpful addition. Further comparative studies would help clarify this

Introduction. Acute ankle injuries are commonly seen in musculoskeletal practice. Surgical management is the gold standard for lateral ligament injury in those with failed conservative treatment for a minimum of six months. Several studies have shown good functional outcome and early rehabilitation after MBG repair with an internal brace augmentation which is a braided ultrahigh molecular weight polyethylene ligament used to enhance the repair that acts as a secondary stabiliser. Hence the aim of the study was to compare the results with and without augmentation. Methods. A single centre retrospective review conducted between November 2017 and October 2019 and this included 172 patients with symptomatic chronic lateral ligament instability with failed conservative management. The diagnosis was confirmed by MRI. All patients had an ankle arthroscopy followed by open ligament repair. Patients were grouped into isolated MBG and internal brace groups for analyses and all had dedicated rehabilitation. Results. A total of 148 patients were available for final follow up with 87 patients in the MBG group and 61 patients in the IBA group. Mean Age was 38 years and mean follow up was 22 months. The internal brace group showed better Manchester Oxford foot and ankle score (19.7 vs 18.2) and more patients returning to preinjury activity levels (73 vs 55) as compared to isolated repair. Conclusion. Internal brace augmentation with MBG repair facilitated early rehabilitation and return to pre injury activity level in majority of patients compared to isolated MBG repair

Anterior cruciate ligament (ACL) graft failure from rupture, attenuation, or malposition may cause recurrent subjective instability and objective laxity, and occurs in 3% to 22% of ACL reconstruction (ACLr) procedures. Revision ACLr is often indicated to restore knee stability, improve knee function, and facilitate return to cutting and pivoting activities. Prior to reconstruction, a thorough clinical and diagnostic evaluation is required to identify factors that may have predisposed an individual to recurrent ACL injury, appreciate concurrent intra-articular pathology, and select the optimal graft for revision reconstruction. Single-stage revision can be successful, although a staged approach may be used when optimal tunnel placement is not possible due to the position and/or widening of previous tunnels. Revision ACLr often involves concomitant procedures such as meniscal/chondral treatment, lateral extra-articular augmentation, and/or osteotomy. Although revision ACLr reliably restores knee stability and function, clinical outcomes and reoperation rates are worse than for primary ACLr. Cite this article: Bone Joint J 2023;105-B(5):474–480

In developmental dysplasia of the hip, a deficient acetabulum may be augmented by placing local autogenous iliac osseous graft, or the ilium itself, over the head of the femur with the expectation that the added bone will function as a bearing surface. We analysed this bone obtained en bloc during subsequent surgery which was performed for degenerative osteoarthritis in three patients at 6, 25 and 30 years after the initial augmentation procedure. In each patient, the augmentation comprised of red cancellous bone covered on its articulating surface by a distinct layer of white tissue. Microscopy of this tissue showed parallel rows of spindle-shaped cells lying between linearly arranged collagen bundles typical of joint capsule. Biochemical analysis showed type I collagen, the principal collagen of joint capsule and bone, with no significant quantity of type II collagen, the principal collagen of cartilage. While the added bone produced by acetabular augmentation was durable, histological and biochemical analyses suggested that it had not undergone cartilage metaplasia. The augmented acetabulum articulates with the head of the femur by means of an interposed hip joint capsule

Abstract. Introduction. Tibial tubercle osteotomy (TTO) is a complex surgical procedure with a significant risk of complications, which include nonunion and tibial fracture. To determine whether an additional suture tape augmentation can provide better biomechanical stability compared with standard screw fixation. Methods. Five matched pairs of human cadaveric knees were divided into 2 groups: the first group underwent standard TTO fixation with 2 parallel screws. The second group underwent a novel fixation technique, in which a nonabsorbable suture tape (FiberTape) in a figure-of-8 construct was added to the standard screw fixation. Tubercular fragment migration of >50% of the initial distalization length was defined as clinical failure Tubercular fragment displacement during cyclic loading and pull-to-failure force were recorded and compared between the 2 groups. Results. The augmented group showed less cyclic tubercular fragment displacement after every load level compared with the standard group, with statistically significant differences starting from 500 N (P < .05; power > 0.8). Mean ± standard deviation tubercular fragment displacement at the end of cyclic loading was 2.56 ± 0.82 mm for the augmented group and 5.21 ± 0.51 mm for the standard group. Mean ultimate failure load after the pull-to-failure test was 2475 ± 554 N for the augmented group and 1475 ± 280 N for the standard group. Conclusion. The specimens that underwent suture tape augmentation showed less tubercular fragment displacement during cyclic loading and higher ultimate failure forces compared with those that underwent standard screw fixation

Rotator cuff repair has excellent clinical outcomes but continues to be a challenge when it comes to large and massive tears as well as revision procedures. Reported symptomatic retear rates are still too high to be acceptable. The purpose of the present study was to evaluate the effectiveness of a combination of augmentation techniques consisting of microfractures of the greater tuberosity, extracellular matrix (ECM) patch graft and subsequent platelet concentrate (PC) subacromial injections in revision rotator cuff repair. The study was designed as a retrospective comparative study on prospectively collected data from a consecutive cohort of patients. All patients who underwent arthroscopic revision rotator cuff repair for symptomatic failure of previous posterosuperior rotator cuff repair were considered eligible for the study. Symptomatic failure had been diagnosed according to clinical examination and confirmed by magnetic resonance imaging (MRI). Structural integrity had been assessed on MRI and classified according to Sugaya classification. Only patients affected by stage IV-V were considered eligible. Tear reparability was confirmed during arthroscopy. Only patients with a minimum 2 years follow-up were included. Patients were divided in two groups. In group 1 (control group) a standard arthroscopic revision and microfractures of the greater tuberosity were performed; in group 2 (experimental group), microfractures of the greater tuberosity and a ECM patch graft were used to enhance tendon repair, followed by postoperative PC injections. Minimum follow-up was 12 months. Primary outcome was the Constant-Murley score (CMS) normalized for age and gender. Subjective outcome was assessed with the Disabilities of the Arm, Shoulder and Hand (DASH) score in its short version (Quick-DASH). Tendon integrity was assessed with MRI at 6 months after surgery. Comparison between groups for all discrete variables at baseline and at follow-up was carried out with the Student's t-test for normally distributed data, otherwise Mann-Whitney U-test was used. Within-group differences (baseline vs follow-up) for discrete variables were analyzed by paired t-test, or by Wilcoxon signed-rank test in case of data with non-normal distribution. Differences for categorical variables were assessed by chi-squared test. Significance was considered for p values < 0.05. Forty patients were included in the study (20 patients for each group). The mean follow-up was 13 ± 1.6 months. No patients were lost at the follow up. Comparison between groups did not show significant differences for baseline characteristics. At follow-up, mean CMS was 80.7 ± 16.6 points in group 1 and 91.5 ± 11.5 points in group 2 (p= 0.022). Mean DASH score was 28.6 ± 21.6 points in group 1 and 20.1 ± 17.4 points in group 2 (p= 0.178). Post-operative MRI showed 6 healed shoulders in Group 1 and 16 healed shoulders in Group 2 (p<0.004). No postoperative complications were reported in both groups. The combination of microfractures of the greater tuberosity, ECM patch graft, and subsequent PC subacromial injections is an effective strategy in improving tendon healing rate

Background. Osteoporotic fracture fixation in the proximal humerus remains a critical challenge. While the biomechanical benefits of screw augmentation with bone cement are established, minimising the cement volume may help control any risk of extravasation and reduce surgical procedure time. Previous experimental studies suggest that it may be sufficient to only augment the screws at the sites of the lowest bone quality. However, adequately testing this hypothesis in vitro is not feasible. Methods. This study systematically evaluated the 64 possible strategies for augmenting six screws in the humeral head through finite element simulations to determine the relative biomechanical benefits of each augmentation strategy. Two subjects with varying levels of local bone mineral density were each modeled with a 2-part and 3-part fracture that was stabilised with a PHILOS plate. The biomechanical fixation was evaluated under physiological loads (muscle and joint reaction forces) that correspond to three different motions: 45 degrees abduction, 45 degrees abduction with 45 degrees internal rotation, and 45 degrees flexion. Results. The higher risk cases (low bone quality or 3-part fracture) exhibited greater peri-implant bone strains and derived greater benefits from screw augmentation. When selecting four screws to augment, the biomechanical benefits ranged from a 25% reduction in bone strain to a 59% reduction in bone strain, depending on the choice of screws. Further, the relative benefits of each augmentation strategy varied between patients and under different loading conditions. Correlations between local bone mineral density and benefits of augmentation were not significant. Conclusions. An optimal augmentation strategy is likely patient-specific and a larger cohort, modeled under a variety of conditions, would be required to elucidate any patient-specific factors (e.g. morphology or bone quality) that may dictate the relative benefits of each augmentation strategy

Objective. To evaluate early mobilization with the ‘STRONG regime’ is safe after lateral ankle ligament repair with suture tape augmentation. Background. The ESSKA-AFAS ankle instability group presented in 2016 evidence-based guidelines for rehabilitation and return to activity after lateral ankle ligament repair. Early mobilization is considered an important element of postoperative rehabilitation. Patients have to be immobilized for approximately six weeks to protect the delicate repair. Lateral ankle ligament repair with suture tape augmentation results in greater strength compared with standard repairs and early mobilization proved to be successful in small sample size studies. Augmented surgery technique is getting increasingly popular. However, it is unknown which rehabilitation regimes are used. It is essential to establish a clear evidence-based guideline for rehabilitation after surgery. Methods. A systematic literature search was performed to obtain the best evidence research regarding this surgery. In cooperation between the orthopaedic- and physical therapy department a post-operative rehabilitation protocol with early mobilization was established. This STRONG protocol (figure 1) is based on milestones and three stages. Results. In February 2016 the first patients were selected for the early mobilization regime. In total 102 patients with a lateral ankle ligament repair were treated with the STRONG protocol. No re-ruptures were observed with a follow up of a year. In a subgroup of athletes hop tests showed a symmetry index of 100,5% for triple hop, 98,6 for side hop and 103,6 for figure of 8 hop. First return to sport was achieved between 9–12 weeks, with full return to competition after a mean of 4 months. Conclusions. An early postoperative mobilization regime based on supervised exercises seems to be a safe intervention after a lateral ankle ligament reconstruction. Clinical implications. Augmented ankle ligament surgery with early mobilization could be an important advancement in treating patients with chronic ankle injuries. For any figures or tables, please contact authors directly

Intervertebral disc (IVD) degeneration is one of the major causes of back pain. A number of emerging treatments for the condition have failed during clinical trial due to the lack of robust biomechanical testing during product development. The aim of this work was to develop improved in-vitro testing methods to enable new therapeutic approaches to be examined pre-clinically. It forms part of a wider programme of research to develop a minimally invasive nucleus augmentation procedure using self-assembling hydrogels. Previous static testing on extracted IVDs have shown large inter-specimen variation in the measured stiffness when specimen hydration and fluid flow were not well controlled. In this work, a method of normalising the hydration state of IVDs prior-to and during compressive testing was developed. Excised adult bovine IVDs underwent water-pik treatment and a 24-hour agitated bath in monosodium citrate solution to maximise fluid mobility. Specimens were submerged in a saline bath and held under constant pressure for 24 hours, after which the rate of change of displacement was low. Specimens were then cyclically loaded, from which the normalised specimen stiffness was determined. A degenerate disc model was developed with the use of enzymatic degeneration, allowing specimens to be tested sequentially in a healthy, degenerate, and then treated state. Self-assembling peptide-GAG hydrogels were tested using the developed method and the effect of treatment on stiffness and disc height were assessed. Compared to previous static tests, the improved method reduced the variation in the normalised specimen stiffness. In addition, statistically significant differences were seen before and after enzymatic degradation to simulate degeneration, thus providing controls against which to evaluate treatments. The augmentation of the nucleus with the hydrogel intervention reduces the stiffness of the degenerate disc towards that of the healthy disc. This method is now being used to further investigate nucleus augmentation devices

Bone defects are occasionally encountered during primary total knee replacement (TKR) and cause difficulty in establishing a stable well-aligned bone-implant interface. Between March 1999 and November 2005, 59 knees in 43 patients underwent primary TKR with a metal block augmentation for tibial bone deficiency. In all, six patients (eight knees) died less than four years post-operatively, and four patients (five knees) were lost to follow-up leaving 46 knees in 33 patients available for review at a mean of 78.6 months (62 to 129). The clinical results obtained, including range of movement, American Knee Society and Oxford knee scores, and the Western Ontario and McMaster Universities osteoarthritis index, were good to excellent, with no failures. Radiolucent lines at the block-cement-bone interface were noted in five knees (11%) during the first post-operative year, but these did not progress. . Modular rectangular metal augmentation for tibial bone deficiency is a useful option. No deterioration of the block-prosthesis or block-cement-bone interface was seen at minimum of five years follow-up

Uncontained peripheral bone defect in posteromedial tibial plateau is not an infrequent problem even in primary total knee arthroplasty, especially in Korean patients some of those have large angular deformities preoperatively. We reviewed the clinical and radiological results of primary total knee replacements of 33 osteoarthritic knees in 28 patients with the use of metal block augmentation for uncontained peripheral tibial bone defects more than 5 millimeters in depth and more than a quarter of medial tibial plateau in width. Those defects were encountered in 75 knees (9.6%) during 779 primary total knee arthroplasties performed by single surgeon between January 2002 and December 2004 at our institution. Modular metal block augmentation was reserved for 42 knees, while the other knees were managed with bone-grafting or cement-filling techniques. Clinical and radiological follow-up more than 12 months were available from 33(78.6%) of 42 knees. At a mean of 32.2 months (range:12~75 months), 31 knees (93.9%) except two cases of failure were evaluated as good or excellent. The average pre-operative American Knee Society Knee and Function scores were 32.5 and 38.6 respectively, which increased to 82.9 and 79.8 respectively at the latest follow-up. There were no radiolucent lines (RLLs) beneath the metallic block or tibial tray, which were progressive or more than 2 millimeters on radiographs, in those knees. Revisions were required for one delayed infection and another aseptic loosening of tibial component. Non-progressive RLLs less than 2 millimeters at the cement-bone interface beneath the metallic block were noted in 10 (32.3%) of 31 knees. The RLLs appeared in 5 (41.7%) of 12 knees with metallic block augmentation alone and 5 (26.3%) of 19 knees which had been treated with the use of additional intramedullary stem augmentation, although this difference was not statistically significant. Since these radiolucent lines were not progressive or symptomatic at all, their clinical meanings or long-term consequences are not determined yet. All knees managed with the additional intramedullary stem augmentation revealed to have radiopaque lines adjacent to the stem on follow-up radiographs. The sclerotic halo around the tip of stem could be interpreted as evidence of the stem’s function in load sharing and might reflect secure fixation of tibial tray to bony interface. We concluded that the use of modular metal block augmentation devices for peripheral tibial defects measuring more than 5 millimeters could provide a simple, rapid and dependable technique that provides predictable results. The observation that all knees managed with additional intramedullary stem augmentation would have sclerotic halo adjacent to the stem on follow-up radiographs may reflect an intramedullary stem is an important adjunct to bone defect management

The purpose of this study was to evaluate the results of selective anatomic augmentation of partial anterior cruciate (ACL) ligament tears in 36 consecutive patients with mean 3years follow-up. Our hypothesis is that this selective augmentation of partial ACL tears could restore knee stability and function. In a consecutive series of 314 ACL reconstructions, 40 patients in which intact ACL fibers remained in the location corresponding to the anteromedial or posterolateral bundle were diagnosed perioperatively. All patients underwent selective augmentation of the torn bundle, while keeping the remaining fibers intact using autogenous hamstring graft. 38 patients (28 males, 10 females) were available with minimum 3 year follow- up. 26 cases had AM bundle tears and 12 cases had PL bundle tears respectively. Patients were assessed with International Knee Documentation Committee (IKDC) 2000 Knee Evaluation Form, Lysholm score; instrumented knee testing was performed with the arthrometer (KT 2000). Statistical analysis was performed to compare the preoperative and postoperative objective evaluation. At 3 year follow-up, 12 (31.6%) patients were graded A, 25 (65.8%) graded B and 1 C (2.6%) at IKDC objective evaluation. Lysholm's score and mean side to side instrumental laxity improved significantly. The results of anatomic single bundle augmentation in partial ACL tears are encouraging with excellent side to side laxity

Introduction. Revision total knee arthroplasy (TKA) has been often used with a metal block augmentation for patients with poor bone quality. However, bone resorption beneath metal block augmentation has been still reported and little information about the reasons of the occurrence of bone resorption is available. The aim of the current study is to identify a possibility of the potential occurrence of bone resorption beneath metal block augmentation, through evaluation of strain distribution beneath metal block augmentation in revision TKA with metal block augmentation, during high deep flexion. Materials and Method. LOSPA, revision TKA with a metal block augmentation (Baseplate size #5, Spacer size #5, Stem size Φ9, L30, Augment #5 T5) was considered in this study. For the test, the tibia component of LOSPA was implanted to the tibia sawbone (left, #3401, Sawbones EuropeAB, Malmö, Sweden), which was corresponded to a traditional TKR surgical guideline. The femoral component of LOSPA was mounted to a customized jig attached to the Instron 8872 (Instron, Norwood, MA, USA), which was designed specially to represent the angles ranged from 0° to 140° with consideration of a rollback of knee joint (Figure. 1). Here, a compressive load of 1,600N (10N/s) was applied for each angle. Strain distribution was then measured from rossete strain gauge (Half Bridge type, CAS, Seoul, Korea) together (Figure 1). Results and Discussions. The strain distribution on the cortical bone of the tibia was shown in Figure 2. The results showed that the strains on the posterior region were gradually increased from extension to high deep of the knee joint and generally larger than the other regions. In contrast to the results on the posterior region, the strains on the medial region were gradually decreased after 60° or 90° flexion position and relatively lower than the other regions. Particularly, the strains on the medial region were generally lower than 50–100 µstrain, which is known as critical value range able to inducing bone resorption, during high deep flexion. This fact indicate that a possibility of the potential bone resorption occurrence in revision TKA used with a metal block augmentation may be relatively increased in patients who are frequently exposed to a personal lifestyle history with the loading conditions of the high flexion. This study may be valuable by identifying for the first time a possibility of the potential bone resorption occurrence through evaluation of the strain distribution beneath metal block augmentation in revision TKA used with a metal block augmentation during high deep flexion. Conclusion. A possibility of the potential bone resorption occurrence in revision TKA used with a metal block augmentation may be dependent on loading patterns applied on the knee joint related to personal lifestyle history. Particularly, it may be relatively increased in patients who are frequently exposed to a personal lifestyle history with the loading conditions of the high flexion. Acknowledgements. This study was supported by a grant from the New Technology Product Evaluation Technical Research project, Ministry of Food and Drug Safety (MFDS), Republic of Korea