Aims. While residual fixed flexion deformity (FFD) in unicompartmental knee arthroplasty (UKA) has been associated with worse functional outcomes, limited evidence exists regarding FFD changes. The objective of this study was to quantify FFD changes in patients with medial unicompartmental knee arthritis undergoing UKA, and investigate any correlation with clinical outcomes. Methods. This study included 136 patients undergoing robotic arm-assisted medial UKA between January 2018 and December 2022. The study included 75 males (55.1%) and 61 (44.9%) females, with a mean age of 67.1 years (45 to 90). Patients were divided into three study groups based on the degree of preoperative FFD: ≤ 5°, 5° to ≤ 10°, and > 10°. Intraoperative optical motion capture technology was used to assess pre- and postoperative FFD. Clinical FFD was measured pre- and postoperatively at six weeks and one year following surgery. Preoperative and one-year postoperative Oxford Knee Scores (OKS) were collected. Results. Overall, the median preoperative navigated (NAV) FFD measured 6.0° (IQR 3.1 to 8), while the median postoperative NAV FFD was 3.0° (IQR 1° to 4.4°), representing a mean correction of 49.2%. The median preoperative clinical FFD was 5° (IQR 0° to 9.75°) for the entire cohort, which decreased to 3.0° (IQR 0° to 5°) and 2° (IQR 0° to 3°) at six weeks and one year postoperatively, respectively. A statistically significant improvement in PROMs compared with baseline was evident in all groups (p < 0.001). Regression analyses showed that participants who experienced a larger FFD correction, showed greater improvement in PROMs (β = 0.609, p = 0.049; 95% CI 0.002 to 1.216). Conclusion. This study found that UKA was associated with an approximately 50% improvement in preoperative FFD across all three examined groups. Participants with greater correction of FFD also demonstrated larger OKS gains. These findings could prove a useful augment to clinical decision-making regarding candidacy for UKA and anticipated improvements in FFD

Fixed flexion deformities are common in osteoarthritic knees that are indicated for total knee arthroplasty. The lack of full extension at the knee results in a greater force of quadriceps contracture and energy expenditure. It also results in slower walking velocity and abnormal gait mechanics, overloading the contralateral limb. Residual flexion contractures after TKA have been associated with poorer functional scores and outcomes. Although some flexion contractures may resolve with time after surgery, a substantial percentage will become permanent. Therefore, it is essential to correct fixed flexion deformities at the time of TKA, and be vigilant in the post-operative course to maintain the correction. Surgical techniques to address pre-operative flexion contractures include: adequate bone resection, ligament releases, removal of posterior osteophytes, and posterior capsular releases. Post-operatively, extension can be maintained with focused physiotherapy, a specially modified continuous passive motion machine, a contralateral heel lift, and splinting

We investigated fixed flexion deformity (FFD) after total knee replacement (TKR). Data relating to 369 cruciate-retaining unilateral TKRs performed at a single institution were collected prospectively. Fixed flexion was measured pre-operatively and at one week, six months, 18 months, three years and five years after surgery. Using binary logistic regression, pre-operative FFD was a predictor of post-operative FFD > 10° at one week (p = 0.006) and six months (p = 0.003) following surgery. Gender was a predictor at one week (p = 0.0073) with 24% of women showing a FFD > 10° compared with 37% of men. We have shown that a gradual improvement in knee extension can be expected up to three years after surgery in knees with FFD. By this time residual FFD is mild or absent in the majority of patients, including those who had a severe pre-operative FFD

Aims. The aim of this study was to assess the effect of posterior cruciate ligament (PCL) resection on flexion-extension gaps, mediolateral soft-tissue laxity, fixed flexion deformity (FFD), and limb alignment during posterior-stabilized (PS) total knee arthroplasty (TKA). Patients and Methods. This prospective study included 110 patients with symptomatic osteoarthritis of the knee undergoing primary robot-assisted PS TKA. All operations were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess gaps before and after PCL resection in extension and 90° knee flexion. Measurements were made after excision of the anterior cruciate ligament and prior to bone resection. There were 54 men (49.1%) and 56 women (50.9%) with a mean age of 68 years (. sd. 6.2) at the time of surgery. The mean preoperative hip-knee-ankle deformity was 4.1° varus (. sd. 3.4). Results. PCL resection increased the mean flexion gap significantly more than the extension gap in the medial (2.4 mm (. sd. 1.5) vs 1.3 mm (. sd. 1.0); p < 0.001) and lateral (3.3 mm (. sd. 1.6) vs 1.2 mm (. sd. 0.9); p < 0.01) compartments. The mean gap differences after PCL resection created significant mediolateral laxity in flexion (gap difference: 1.1 mm (. sd. 2.5); p < 0.001) but not in extension (gap difference: 0.1 mm (. sd. 2.1); p = 0.51). PCL resection significantly improved the mean FFD (6.3° (. sd. 4.4) preoperatively vs 3.1° (. sd. 1.5) postoperatively; p < 0.001). There was a strong positive correlation between the preoperative FFD and change in FFD following PCL resection (Pearson’s correlation coefficient = 0.81; p < 0.001). PCL resection did not significantly affect limb alignment (mean change in alignment: 0.2° valgus (. sd. 1.2); p = 0.60). Conclusion. PCL resection creates flexion-extension mismatch by increasing the flexion gap more than the extension gap. The increase in the lateral flexion gap is greater than the increase in the medial flexion gap, which creates mediolateral laxity in flexion. Improvements in FFD following PCL resection are dependent on the degree of deformity before PCL resection. Cite this article: Bone Joint J 2019;101-B:1230–1237

We reviewed the results of anterior hip release for fixed flexion deformity in 57 hips in 38 children with spina bifida at an average follow-up of 8.9 years (2 to 22). The indication for this operation was a fixed flexion deformity of more than 30° which interfered with function. In 43 hips there was a good outcome in that the fixed flexion deformity remained less than 30° at follow-up. Four hips had a good initial result but deteriorated after an average of five years, and ten had a poor outcome with deformity of over 30°. Six hips required a repeated anterior hip release and two of these were successful. The success of anterior hip release could not be related to the neurological level or the age at operation. Successful surgery correlated with the walking ability of the child at the latest follow-up

Aims. The objectives of this study were to assess the effect of anterior cruciate ligament (ACL) resection on flexion-extension gaps, mediolateral soft tissue laxity, maximum knee extension, and limb alignment during primary total knee arthroplasty (TKA). Methods. This prospective study included 140 patients with symptomatic knee osteoarthritis undergoing primary robotic-arm assisted TKA. All operative procedures were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess study outcomes pre- and post-ACL resection with knee extension and 90° knee flexion. This study included 76 males (54.3%) and 64 females (45.7%) with a mean age of 64.1 years (SD 6.8) at time of surgery. Mean preoperative hip-knee-ankle deformity was 6.1° varus (SD 4.6° varus). Results. ACL resection increased the mean extension gap significantly more than the flexion gap in the medial (mean 1.2 mm (SD 1.0) versus mean 0.2 mm (SD 0.7) respectively; p < 0.001) and lateral (mean 1.1 mm (SD 0.9) versus mean 0.2 mm (SD 0.6) respectively; p < 0.001) compartments. The mean gap differences following ACL resection did not create any significant mediolateral soft tissue laxity in extension (gap difference: mean 0.1 mm (SD 2.4); p = 0.89) or flexion (gap difference: mean 0.2 mm (SD 3.1); p = 0.40). ACL resection did not significantly affect maximum knee extension (change in maximum knee extension = mean 0.2° (SD 0.7°); p = 0.23) or fixed flexion deformity (mean 4.2° (SD 3.2°) pre-ACL release versus mean 3.9° (SD 3.7°) post-ACL release; p = 0.61). ACL resection did not significantly affect overall limb alignment (change in alignment = mean 0.2° valgus (SD 1.0° valgus; p = 0.11). Conclusion. ACL resection creates flexion-extension mismatch by increasing the extension gap more than the flexion gap. However, gap differences following ACL resection do not create any mediolateral soft tissue laxity in extension or flexion. ACL resection does not affect maximum knee extension or overall limb alignment. Cite this article: Bone Joint J 2020;102-B(4):442–448

Between 1990 and 1996 we performed 20 consecutive ulnohumeral arthroplasties for primary osteoarthritis of the elbow. The outcome was assessed using the Disabilities of Arm, Shoulder and Hand Score (DASH) and the Mayo Elbow Performance Score (MEPS) at a mean follow-up of 75 months (58 to 132). There were excellent or good results in 17 elbows (85%) using the DASH score and in 13 (65%) with the MEPS (correlation coefficient 0.79). The mean fixed flexion deformity had improved by 10° and the range of flexion by a mean of 20°. In 16 elbows (80%) the benefits of surgery had been maintained, and of 16 patients working at the time of operation, 12 (75%) had returned to the same job. There was no correlation between radiological recurrence of degenerative changes and the amount of fixed flexion deformity, the flexion arc, or the elbow scores

We report the results of anterior soft-tissue release of the hip for fixed flexion deformity in 17 patients (31 hips) with juvenile chronic arthritis. The mean age at operation was 8 years 6 months. All the patients were reviewed at one and three years and 11 (21 hips) were available for review at five years. The results were good as regards early pain relief and improved mobility. At one year, the average fixed flexion deformity was reduced from 35 degrees to 9.5 degrees, and at three years it was 18 degrees. This degree of improvement was maintained in the hips followed for five years. At 5 to 12 years' follow-up (mean 6.7) seven patients (14 hips) have required no further surgery and have maintained an acceptable range of motion. We discuss the influence of surgery on radiographic changes and on femoral neck anteversion

Aims. The purpose of this study was to report the experience of dynamic intraligamentary stabilisation (DIS) using the Ligamys device for the treatment of acute ruptures of the anterior cruciate ligament (ACL). Patients and Methods. Between March 2011 and April 2012, 50 patients (34 men and 16 women) with an acute rupture of the ACL underwent primary repair using this device. The mean age of the patients was 30 years (18 to 50). Patients were evaluated for laxity, stability, range of movement (ROM), Tegner, Lysholm, International Knee Documentation Committee (IKDC) and visual analogue scale (VAS) scores over a follow-up period of two years. Results. At final follow-up, anteroposterior translation differed from the normal knee by a mean of 0.96 mm (-2 mm to 6 mm). Median (interquartile range) IKDC, Tegner, Lysholm and VAS scores were 98 (95 to 100), 6 (5 to 7), 100 (98 to 100) and 10 (9 to 10), respectively. Pre-injury Tegner activity levels were reached one year post-operatively. A total of nine patients (18%) required a secondary intervention; five developed instability, of whom four underwent secondary hamstring reconstructive surgery, and five required arthroscopic treatment for intra-articular impingement due to scar tissue which caused a fixed flexion deformity. In addition, 30 patients (60%) required removal of the tibial screw. Conclusion. While there was a high rate of secondary interventions, 45 patients (90%) retained their repaired ACL two years post-operatively, with good clinical scores and stability of the knee. Take home message: Dynamic intraligamentary stabilisation presents a promising treatment option for acute ACL ruptures, eliminating the need for ACL reconstruction. Cite this article: Bone Joint J 2016;98-B:793–8

A congenital, unilateral, fixed flexion deformity in a neonate was diagnosed as a congenital absence of the knee. A single cartilage mass, with fusion of the lower femoral and upper tibial ossification centres, was demonstrated by imaging studies. This condition has been reported in the literature only once before. Surgery on our patient, which was performed at the age of two years, consisted of separation of the fused cartilaginous anlage and gradual correction of the deformity using an Ilizarov frame

We have used the Ilizarov technique for severe flexion deformity of the knee in 11 patients (13 knees) between 1986 and 1994 and have followed them up for an average of 4.1 years. The age of the patients at operation ranged from 1.7 to 18.8 years. The femoral and tibial components were connected by two anterior hinges, medial and lateral, and two posterior distraction rods. The deformity was corrected to a femorotibial lateral shaft angle of less than 20°. A permanent orthosis was applied after removal of the fixator. Fractures occurred in four patients and paralysis of the common peroneal nerve in another. There was a recurrence of the deformity in four patients. At the last review all patients were able to walk on their operated leg with or without an orthosis. We have found the Ilizarov method to be helpful in correcting severe fixed flexion deformity of the knee, with relatively few complications, but the basic principles of the method must be carefully followed

We review 210 Stanmore knee replacements in 163 patients to assess the survival of the prostheses and the long-term results. The annual rate of failure reached a maximum of 4.6% in the fourth year after operation; thereafter it declined to reach zero by the eighth year. Between two and eight years after operation, 66.3% of the surviving knees were completely free of pain and 30.2% had mild retropatellar pain. Fixed flexion deformities present before operation were completely corrected in 73% of the knees, and varus or valgus deformities were invariably corrected. Stability was always restored to unstable knees and 80.8% of knees flexed to 90 degrees or more after replacement. Aseptic loosening (8.1%), prosthetic infection (4.3%) and femoral fracture (2.9%) led to 8.5% of the prostheses being revised or removed over eight years. Modifications in prosthetic design and operative techniques have been introduced to minimise such complications in the future

Aims

Total knee arthroplasty (TKA) with a highly congruent condylar-stabilized (CS) articulation may be advantageous due to increased stability versus cruciate-retaining (CR) designs, while mitigating the limitations of a posterior-stabilized construct. The aim was to assess ten-year implant survival and functional outcomes of a cemented single-radius TKA with a CS insert, performed without posterior cruciate ligament sacrifice.

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Robotic arm-assisted surgery offers accurate and reproducible guidance in component positioning and assessment of soft-tissue tensioning during knee arthroplasty, but the feasibility and early outcomes when using this technology for revision surgery remain unknown. The objective of this study was to compare the outcomes of robotic arm-assisted revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) versus primary robotic arm-assisted TKA at short-term follow-up.

Between June 1993 and December 1994, we performed total knee arthroplasty (TKA) on 27 knees in 24 patients with spontaneous bony ankylosis in severe flexion. The mean age at operation was 43.5 years (30 to 60). No patient had preoperative pain. Three were unable to walk and 21 could manage less than five blocks. The mean duration of the ankylosis was 18.7 years (13 to 25) and its mean position was 105° flexion (75 to 135). The preoperative Hospital for Special Surgery Knee Score of 60 points was improved to 87 at the final follow-up three to five years later. All knees were free from pain. The mean range of active flexion in 24 knees was 97° (78 to 115) and the mean arc of movement 91° (78 to 98). The mean fixed flexion deformity was 6° (0 to 25) and the extension lag 8° (0 to 25). Angular deformity was corrected to between 0° and 10° of valgus. Four patients were able to walk one block and 20 five to seven blocks. Thirteen knees (48%) showed some necrosis at the skin edge; one knee required arthrodesis and another resection arthroplasty. One had a recurrence of tuberculous infection requiring arthrodesis. One patient had a rupture of the quadriceps tendon. To date no prosthesis has required revision for loosening. Radiolucency of 1 mm or less about the tibial prosthesis was observed at follow-up in four of the 24 knees. Our results have shown that one-stage TKA and skeletal traction after operation can achieve correction of severe flexion deformity of the knee with marked improvement in the function and quality of life

We report a prospective randomly controlled trial to examine the effectiveness of continuous passive motion (CPM) in improving postoperative function and range of movement after total knee arthroplasty (TKA). We allocated 53 patients (57 knees) to one of three postoperative regimes: no CPM (n = 19); CPM at 0 to 40° (0 to 40 CPM; n = 18); and CPM at 0 to 70° (0 to 70 CPM; n = 20). Those in the CPM groups had CPM for 48 hours and all patients had an identical regime of physiotherapy. There was an even distribution of various cemented and cementless TKAs in each group. Patients were assessed preoperatively and at one week and at one year postoperatively. At one week, there was a statistically significant increase in the range of flexion and total range of movement in the 0 to 70 CPM group compared with the no-CPM group. At one year we found no significant differences in mean flexion, overall range of movement, fixed flexion deformity or functional results in the three groups. Those who had CPM had a significant increase in analgesic requirement (p = 0.04). There was an increased mean blood drainage postoperatively in those who had 0 to 70 CPM (1558 ml) compared with those with no CPM (956 ml) (t = 2.96, p = 0.005) and with 0 to 40 CPM (1017 ml) (t = 2.62, p = 0.01). Our findings show that CPM had no significant advantage in terms of improving function or range of movement, and that its use increased blood loss and analgesic requirements

Aims

Reconstruction after osteoarticular resection of the proximal ulna for tumours is technically difficult and little has been written about the options that are available. We report a series of four patients who underwent radial neck to humeral trochlea transposition arthroplasty following proximal ulnar osteoarticular resection.

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The ulna is an extremely rare location for primary bone tumours of the elbow in paediatrics. Although several reconstruction options are available, the optimal reconstruction method is still unknown due to the rarity of proximal ulna tumours. In this study, we report the outcomes of osteoarticular ulna allograft for the reconstruction of proximal ulna tumours.

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Total femoral arthroplasty (TFA) is a rare procedure used in cases of significant femoral bone loss, commonly from cancer, infection, and trauma. Low patient numbers have resulted in limited published work on long-term outcomes, and even less regarding TFA undertaken for non-oncological indications. The aim of this study was to evaluate the long-term clinical outcomes of all TFAs in our unit.

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The aim of this study was to evaluate the reliability and validity of a patient-specific algorithm which we developed for predicting changes in sagittal pelvic tilt after total hip arthroplasty (THA).

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The aim of this study was to compare a bicruciate-retaining (BCR) total knee arthroplasty (TKA) with a posterior cruciate-retaining (CR) TKA design in terms of kinematics, measured using fluoroscopy and stability as micromotion using radiostereometric analysis (RSA).

We aim to explore the potential technologies for monitoring and assessment of patients undergoing arthroplasty by examining selected literature focusing on the technology currently available and reflecting on possible future development and application. The reviewed literature indicates a large variety of different hardware and software, widely available and used in a limited manner, to assess patients’ performance. There are extensive opportunities to enhance and integrate the systems which are already in existence to develop patient-specific pathways for rehabilitation.

Cite this article: Bone Joint J 2022;104-B(10):1104–1109.

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The aim of this study was to investigate the feasibility of application of a 3D-printed megaprosthesis with hemiarthroplasty design for defects of the distal humerus or proximal ulna following tumour resection.

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The aim of this study was to compare any differences in the primary outcome (biphasic flexion knee moment during gait) of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) at one year post-surgery.

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Total knee arthroplasty (TKA) using functional alignment aims to implant the components with minimal compromise of the soft-tissue envelope by restoring the plane and obliquity of the non-arthritic joint. The objective of this study was to determine the effect of TKA with functional alignment on mediolateral soft-tissue balance as assessed using intraoperative sensor-guided technology.

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Higher osteoblastic bone activity is expected in aseptic loosening and painful unicompartmental knee arthroplasty (UKA). However, insights into normal bone activity patterns after medial UKAs are lacking. The aim of this study was to identify the evolution in bone activity pattern in well-functioning medial mobile-bearing UKAs.

We assessed the outcome after simultaneous multiple operations performed on 18 children with spastic diplegia, with emphasis on the changes in the physiological cost index (PCI) of walking. Fourteen patients had a measurable reduction at one year, but the more severely affected patients took up to two years to reach a new functional plateau. The level of the preoperative PCI allows prediction of the outcome of surgery in terms of reducing the effort of walking, or improving its appearance only. Intrapelvic intramuscular psoas tenotomy produced an improvement of hip flexion deformity in 15 of 17 patients without the loss of muscle power to initiate the swing phase. Fractional lengthening corrected hamstring tightness in 17 cases, and the mean popliteal angle was reduced from 63 degrees preoperatively to 30.2 degrees, with almost complete resolution of the fixed knee flexion deformity present in ten patients. Distal transfer of the rectus femoris, when it was shown to be contracting inappropriately, improved the knee flexion arc during walking from a mean of 28.3 degrees to 45.2 degrees

Aims

Modern total knee arthroplasty (TKA) prostheses are designed to restore near normal kinematics including high flexion. Kneeling is a high flexion, kinematically demanding activity after TKA. The debate about design choice has not yet been informed by six-degrees-of-freedom in vivo kinematics. This prospective randomized clinical trial compared kneeling kinematics in three TKA designs.

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In the UK, fasciectomy for Dupuytren’s contracture is generally performed under general or regional anaesthetic, with an arm tourniquet and in a hospital setting. We have changed our practice to use local anaesthetic with adrenaline, no arm tourniquet, and perform the surgery in a community setting. We present the outcome of a consecutive series of 30 patients.

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The aims of this study were to determine the change in the sagittal alignment of the pelvis and the associated impact on acetabular component position at one-year follow-up after total hip arthroplasty (THA).

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An algorithm to determine the constitutional alignment of the lower limb once arthritic deformity has occurred would be of value when undertaking kinematically aligned total knee arthroplasty (TKA). The purpose of this study was to determine if the arithmetic hip-knee-ankle angle (aHKA) algorithm could estimate the constitutional alignment of the lower limb following development of significant arthritis.

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Our objective is to describe our early and mid-term results with the use of a new simple primary knee prosthesis as an articulating spacer in planned two-stage management for infected knee arthroplasty. As a second objective, we compared outcomes between the group with a retained first stage and those with a complete two-stage revision.

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It remains controversial whether patellofemoral joint pathology is a contraindication to lateral unicompartmental knee arthroplasty (UKA). This study aimed to evaluate the effect of preoperative radiological degenerative changes and alignment on patient-reported outcome scores (PROMs) after lateral UKA. Secondarily, the influence of lateral UKA on the alignment of the patellofemoral joint was studied.

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The aims of this study were to determine the effect of osteophyte excision on deformity correction and soft tissue gap balance in varus knees undergoing computer-assisted total knee arthroplasty (TKA).

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Double-level lengthening, bone transport, and bifocal compression-distraction are commonly undertaken using Ilizarov or other fixators. We performed double-level fixator-assisted nailing, mainly for the correction of deformity and lengthening in the same segment, using a straight intramedullary nail to reduce the time in a fixator.

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The aim of this study was to evaluate the prosthesis characteristics and associated conditions that may modify the survival of total femoral endoprosthetic replacements (TFEPR).

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The purpose of this study was to report the long-term results of extendable endoprostheses of the humerus in children after the resection of a bone sarcoma.

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Limited evidence is available on mid-term outcomes of robotic-arm assisted (RA) partial knee arthroplasty (PKA). Therefore, the purpose of this study was to evaluate mid-term survivorship, modes of failure, and patient-reported outcomes of RA PKA.

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Altered alignment and biomechanics are thought to contribute to the progression of osteoarthritis (OA) in the native compartments after medial unicompartmental knee arthroplasty (UKA). The aim of this study was to evaluate the bone activity and remodelling in the lateral tibiofemoral and patellofemoral compartment after medial mobile-bearing UKA.

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Between 15% and 20% of patients remain dissatisfied following total knee arthroplasty (TKA). The SAIPH knee system (MatOrtho, Surrey, United Kingdom) is a medial ball and socket TKA that has been designed to replicate native knee kinematics in order to maximize the range of movement, stability, and function. This system is being progressively introduced in a stepwise fashion, with this study reporting the mid-term clinical and radiological outcomes.

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The results of kinematic total knee arthroplasty (KTKA) have been reported in terms of limb and component alignment parameters but not in terms of gap laxities and differentials. In kinematic alignment (KA), balance should reflect the asymmetrical balance of the normal knee, not the classic rectangular flexion and extension gaps sought with gap-balanced mechanical axis total knee arthroplasty (MATKA). This paper aims to address the following questions: 1) what factors determine coronal joint congruence as measured on standing radiographs?; 2) is flexion gap asymmetry produced with KA?; 3) does lateral flexion gap laxity affect outcomes?; 4) is lateral flexion gap laxity associated with lateral extension gap laxity?; and 5) can consistent ligament balance be produced without releases?

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The aim of this study was to describe, analyze, and compare the survival, functional outcome, and complications of minimally invasive (MI) and non-invasive (NI) lengthening total femoral prostheses.

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The objectives of this study were to compare postoperative pain, analgesia requirements, inpatient functional rehabilitation, time to hospital discharge, and complications in patients undergoing conventional jig-based unicompartmental knee arthroplasty (UKA) versus robotic-arm assisted UKA.