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

Abstract. Introduction. This study compared biomechanical and functional parameters of a total knee arthroplasty (TKA) implant (Cemented Zimmer Hi-Flex) against healthy older adults to determine whether knee biomechanics was restored in this patient population. Methodology. Patients with a primary TKA and healthy adults >55 years old with no musculoskeletal deficits or arthritis participated. Bilateral knee range of motion (RoM) was assessed with a goniometer, then gait patterns were analysed with a 3D motion-capture system. An arthrometer then quantified anterior-posterior laxity of each knee. Statistical analyses were performed in SPSS (α=0.05; required sample size: n=21 per group). Results. 25 knees were replaced in 21 patients. Nine presented with fixed flexion deformities (FFD) (13.3±5.6°). FFDs were abolished intraoperatively, and the average flexion increased from 124.8±9.1° to 130.9±5.8°. At 9.6±3.2 years postoperatively, the patients achieved poorer RoM than healthy controls (n=23); p<0.0001. These differences were due to limited flexion in the knee. Patients also failed to achieve the same degree of flexion as controls bilaterally during gait. No differences were observed during mid-flexion; a state that has been associated with instability (p=0.614). There were no differences between groups in knee laxity. Conclusion. Patients in this study had similar gait patterns to healthy older adults during mid-flexion, and were no more likely to exhibit anterior-posterior translation of the knee >7mm; a known risk factor of instability. However, the flexion range was poorer. This led to bilateral pathological knee flexion patterns during gait. Further research should identify the cause of these limitations

Introduction. At Sheffield Children's Hospital, treatment of leg length discrepancy is a common procedure. Historically, this has been done with external fixators. With the development in intramedullary technology, internal nails have become the preferred modality for long bone lengthening in the adolescent population. However, it is important to review whether this technology practically reduces the known challenges seen and if it brings any new issues. Therefore, the aim of this review is to retrospectively evaluate the therapeutic challenges of 16 fit-bone intramedullary femoral lengthening's at Sheffield Children's Hospital between 2021–2022. Materials & Methods. The international classification of function (ICF) framework was used to differentiate outcomes. The patient's therapy notes were retrospectively reviewed for themes around structural, activity and participation limitation. The findings were grouped for analysis and the main themes presented. Results. There were 8 males, mean age 17.4 years (range 17–18) and 8 females, mean age 15.9 years (range 14–18). 5 right and 11 left femurs were lengthened. Underlying pathology varied amongst the 16 patients. All patients went into a hinged knee brace post operatively. Structural limitations included: pain, fixed flexion deformity of the knee, loss of knee flexion, quadriceps muscle lag, muscle spasms and gluteal weakness. The primary activity limitation was reduced weight bearing with altered gait pattern. Participation limitations included reduced school attendance and involvement in activities with peers. Access to Physiotherapy from local services varied dramatically. Five of the cohort have completed treatment. Conclusions. Anecdotally, intramedullary femoral lengthening nails have perceived benefits for families compared to external fixators in the adolescent population. However, there remain musculoskeletal and psychosocial outcomes requiring therapeutic management throughout the lengthening process and beyond. Therefore, quantifying these outcomes is essential for measuring the impact on each patient for comparison. To interpret these themes, we need to evaluate the outcomes objectively, this was not done consistently in this review. Future research should look at outcome measures that are sensitive to all aspects of the ICF. With an aim of improving the therapeutic treatment provided and the overall outcome for the children treated

Introduction. The objective of this study was to assess the effect of PCL resection on flexion-extension gaps, mediolateral soft tissue laxity, fixed flexion deformity (FFD), and limb alignment during posterior-stabilised total knee arthroplasty (TKA). Methods. This prospective study included 110 patients with symptomatic knee osteoarthritis undergoing primary robotic-arm assisted posterior-stabilised 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 gaps pre- and post-PCL resection in knee extension and 90 degrees knee flexion. This study included 54 males (49.1%) and 56 females (50.9%) with a mean age of 68 ± 6.2 years at time of surgery. Mean preoperative hip-knee-ankle deformity was 6.1 ± 4.4 degrees varus. Results. PCL resection increased the flexion gap more than the extension gap in the medial (2.4 ± 1.5mm vs 1.3 ± 1.0mm respectively, p<0.001) and lateral (3.3 ± 1.6mm vs 1.2 ± 0.9mm respectively, p<0.01) compartments. The gap differences following PCL resection created mediolateral laxity in flexion (gap difference: 1.1 ± 2.5mm, p<0.001) but not in extension (gap difference: 0.1 ± 2.1mm, p=0.51). PCL resection improved overall FFD (6.3 ± 4.4° preoperatively vs 3.1 ± 1.5° postoperatively, p<0.001). There was a strong positive correlation between preoperative FFD and change in FFD following PCL release (Pearson correlation coefficient = 0.81, p<0.001). PCL resection did not affect overall limb alignment (change in alignment: 0.2 ± 1.2 degrees valgus, p=0.60). Conclusion. PCL resection creates flexion-extension mismatch by increasing the flexion gap proportionally more than the extension gap. The increase in the lateral flexion gap is greater than the increase in medial flexion gap, which creates mediolateral laxity in flexion. Improvements in FFD following PCL resection are dependent on the degree of deformity prior to PCL resection. Bone resection, implant positioning, and periarticular soft tissue balancing should account for these changes in flexion-extension gaps, mediolateral laxity, and fixed flexion deformity following PCL resection in PS TKA. For figures, tables, or references, please contact authors directly

Fixed flexion deformity is common in neglected cases of advanced arthritis of the knee. The need and means of complete correction of fixed flexion deformity remains controversial. We analysed 60 patients of advanced arthritis with severe flexion deformity > 300 who underwent total knee arthroplasty between January 2002 to January 2008. The age ranged from 54 to 78 years (mean age of 62 years). All surgeries were performed using posterior cruciate substituting implant. Patients were followed for an average period of 42 months. All patients were operated in a single stage. Distal femoral over-resection was done in addition to posterior, postero-medial and postero-lateral release. Posterior release was done upto the linea aspera. In 2 cases posterior capsular was released directly. A criteria was developed for sequential release on the basis of degree of flexion deformity. Flexion deformity was fully corrected in 48 cases where as 50 of residual flexion remained in 5 cases with preoperative deformity of 40–600 and 100 residual flexion remained in 6 cases with preoperative deformity > 600. One patient with pre op fixed flexion deformity of 90* had to be treated with arthrodesis. Our experience suggest that predetermined routine femoral over-resection in moderate to severe flexion deformity prior to balancing knee is not fraught with complications if our criteria are followed. Additional bony cuts (over-resection) and posterior soft tissue release is complementary to each other in correction of flexion deformity and it should be a sequential release. This technique saves time, reduces intraoperative difficulties and helps to correct flexion deformity maximally

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

Introduction. We propose that Total Hip Replacement with correction of fixed flexion deformity of the hip and exaggerated lumbar lordosis will result in relief of symptoms from spinal stenosis, possibly avoiding a spinal surgery. A sequence of patients with this dual pathology has been assessed to examine this and suggest a possible management algorithm. Materials and methods. A retrospective study of 19 patients who presented with dual pathology was performed and the patients were assessed with regards to pre and post-operative symptoms, walking distance, and neurological status. Results. There were 17 patients with improvement in the spinal stenotic symptoms following hip replacement to an extent that none required spinal surgery. There were two patients who had spinal surgery after THR, at varying lengths following hip replacements as their spinal stenotic symptoms worsened over time, and had lateral spinal stenosis on MRI. Discussion. In advanced hip osteoarthritis, a fixed flexion deformity may develop at the hip leading to an exaggerated lumbar lordosis in erect posture. In the presence of co-existing spinal stenosis, the exaggerated lumbar lordosis may worsen the spinal stenotic symptoms while standing and walking. Cadaveric & Radiological studies have shown that canal narrowing occurs with increased lordosis/ extension in the lumbar spine. Our findings suggest that when central lumbar spinal stenosis coexists with bilateral hip arthritis and FFD at the hip, THR should be offered first. Successful hip surgery for arthritis correcting significant fixed flexion deformity would lessen the lumbar lordosis, thus correcting the excessive pathological narrowing. If a patient is fit enough, simultaneous bilateral THR via an anterior type of approach makes surgical correction of FFD easier. Although it has been suggested in the literature that patients with spinal stenosis have a increased risk of neurological impairment following THR, we did not find any clear association

Total Knee Joint Replacement is mostly commonly performed using a measured resection technique. When the PCL is retained 9mm of bone is resected off the distal femur. If the PCL is excised 11m of bone is resected. Computer assisted total knee joint replacement will guide the surgeon to perform the optimal distal femoral resection to gain neutral alignment and full post operative extension. Three hundred TKJR’s were performed by one surgeon using the De Puy Ci navigation system. A ligament balancing technique is used whereby a neutral tibial resection is performed. A ligament tensor is inserted in extension and flexion. The navigation system then performs an optimization process whereby the distal femoral cut is calculated to give a neutral mechanical axis and 0° of knee extension. Data was collected measuring the distal femoral resection in the PCL retained and resected knees. The distal femoral cut required to achieve full extension for the PCL retaining TKJR ranged from 5 – 15mm. The mean was 11.2mm. The distal femoral cut required to achieve full extension for the PCL sacrificing TKJR ranged from 5 – 15mm. The mean was 10.8mm. There was no difference between the two groups (p=0.07). Both the PCL retaining and sacrificing TKJR distal resections correlated with the preoperative flexion deformity, i.e. patients with a greater fixed flexion deformity required a greater distal femoral resection to achieve full extension. There is a wide variation in the distal femoral cut to achieve full extension in TKJR. It is accepted that a smaller distal resection is required for a PCL retaining than a PCL sacrificing TKJR. Our study refutes this premise. A greater femoral resection is required if there is a greater fixed flexion deformity. A measured resection technique will result in a large percentage of patients with a fixed flexion deformity following TKJR

Purpose: Arthrogryposis is a disease of muscular system, which is characterized by fibrous degeneration of muscles that leads to deformed and rigid joints. Aim of this study is to describe the deformities of the lower limbs and their surgical treatment. Material – Methods: Twenty children (12 boys-8 girls) with distal arthrogyposis were treated in our department during the decade 1992–2002. The deformities of lower extremities were referred to hip, knee and foot. Congenital dislocation of hip joint was noticed in 4 patients that were treated by open reduction, while fixed flexion and adduction deformity was appeared in 8 patients that were treated by release of flexors and adductors muscles of hip. The main deformity in knee was fixed flexion deformity (19 patients), while hyperextension was presented only in one patient. The flexed knee was corrected with release or lengthening of hamstrings. The most frequent foot deformities were equinovarus deformity (17 patients) and fixed flexion deformity of toes (15 patients). Club foot was treated by posteromedial capsulectomy, lengthening of Achilles tendon, release of posterior tibialis and transfer of anterior tibialis in the lateral aspect of foot, while fixed flexion deformity of toes were corrected by release of flexor longus digitorum and palmar aponeurosis. Results: All patients had postoperative correction of the deformities. Recurrence of the deformities was noticed in all patients after two years. Fifteen patients were re-operated 4 years after the first surgical treatment. Conclusion: High degree of recurrent deformities of lower limbs is appeared after their surgical treatment, but this treatment is the only one for patients with distal arthrogryposis in order to succeed independent ambulation

The hip joints are commonly affected in Juvenile Idiopathic Arthritis (JIA) in childhood. Common features are pain, subluxation, femoral anteversion, coxa valga, significant fixed flexion deformity and a true arthritis, with loss of articular cartilage principally from the femoral head but also the acetabulum. In children with JIA, it is accepted that a medial soft tissue release of the hips, dividing adductor longus, adductor brevis and the ilio-psoas, is a useful tool in the management of significant hip joint involvement. The principal indication for surgery is the relief of pain, but other benefits are correction of fixed flexion deformity, restoration of articular cartilage, increased abduction of the hips and, in those children who are unable to walk, frequently a transition to the potential to walk. The procedure is nearly always performed bilaterally. Our study aimed to document the restoration of articular cartilage at the hips following soft tissue release. It has been noted in the literature that there is regrowth of articular cartilage in the hip but there has been no true documentation of this and x-ray studies are unreliable as the elimination of fixed flexion deformity can prejudice accurate analysis of femoral head geometry on 2 –dimensional views. We therefore carried out MRI scanning of the hips, immediately prior to the soft tissue release and 12–18 months post-operatively. In 10 consecutive patients analysed, scans demonstrated true articular cartilage regrowth in 8 cases. We thus conclude that soft tissue release of the hips in JIA is a useful management tool, and may to some extent reverse the severe articular cartilage loss seen in these children. The next stage of our study is to analyse the articular cartilage at the time of subsequent hip arthroplasty to determine whether true hyaline cartilage is reformed or whether the reconstitute represents fibrocartilage

Introduction. We have previously published limb lengthening using external fixation in pathological bone diseases. We would like to report a case series of femoral lengthening using the PRECICE system in a similar pathological group especially looking at it's feasibility and complications. Materials and Methods. This is a case series of four patients, two patients with osteogenesis imperfecta and two with Ollier's disease, who underwent femoral lengthening via distraction osteogenesis using the PRECICE intramedullary nail system. It was a retrospective study from a prospective database from clinical records and radiographs. Results. The mean age at the time of surgery was 15.5 years, the mean preoperative leg length discrepancy was 30mm, and the mean distraction distance achieved was 28.75mm. Since these patients were of shorter heigh, limb lengthening was considered. All 4 patients had successful insertion of the nail. The outcomes noted from the 4 patients are collated, with several complications occurring including delayed femoral union, fixed flexion deformity of the hip, persisting pain and quadriceps weakness. Those with Ollier's disease underwent an increased rate of distraction to prevent premature healing. The implications of long-term bisphosphonate therapy in OI are discussed with regards to the risk of delayed femoral union and intra-operative fracture. Conclusions. Intramedullary femoral lengthening in pathological bone disease is possible, but the surgeon needs to give attention to certain details. The regenerate formation is based on the background pathology irrespective of the hardware used. There is much more compliance with the nail technique

Introduction: Stiffness following total knee arthroplasty is a disabling problem resulting in pain and reduced function. Prevalence is not well defined and although various treatment modalities including manipulation, arthrolysis and revision surgery has been proposed with varying degrees of success for reduced flexion, these Methods: are deemed to be of limited value in fixed flexion deformity (FFD). There is limited literature on the natural history of FFD which is important to the decision process. The aim of our study was to evaluate the natural course of FFD following primary total knee arthroplasty. Methods: Prospective review of a consecutive series of 1768 patients who underwent primary total knee arthroplasty over a 7 year (2001 to 2008) period. Demographic data included post-operative range of motion; type of prosthesis used, treatment modalities for stiffness and the final range of motion were recorded. FFD was defined as class 1(hyperextension to 0), Class 2 (1–10 degrees), Class 3(11–20 degrees) and Class 4(> 20 degrees). All patients were reviewed by an independent reviewer (senior physiotherapist). All patients were followed from 6 weeks post surgery until FFD completely resolved or improved to patient satisfaction. Patients with infection, stiffness treated with manipulation or revision surgery were excluded from the study. Patients lost to follow-up were noted. Results: Of the 1768 patients evaluated, 180 (10.2%) presented with a FFD. A total number of 18 patients were excluded from the study and 16 were lost to follow up. None (0%) were class 1, 134 (91.8%) were class 2, 10 (6.9%) were class 3 and 2 (1.4%) were class 4. The FFD group had a mean age of 60.5. Follow up period ranged from 1.3 to 63.3 months and the FFD improved from a mean of 8.16 degrees to 0.15 degrees (p< 0.001). In 94.5% patients the FFD completely resolved (i.e. < 5 deg) at a mean of 9.76 months. In the remaining 5.5% of patients, FFD improved from a mean of 16.4 to 6.9 degrees at a mean follow up of 15.5 months and was found to cause no functional deficit. Conclusion: The overall prevalence of fixed flexion deformity is 10.2 % with only 0.7% in Class 3 and Class 4, which is comparable with the literature. The majority of patients will see a resolution of their fixed flexion deformity in less than 10 months with routine post operative physiotherapy. The small number of patients left with a residual FFD did not appear to suffer a functional deficit. Patients found to have a post operative FFD should be reassured and encouraged to participate in a standardised post operative physiotherapy regime

Flexion contractures are a common finding in an end-stage arthritic knee, occurring in up to 60% of patients undergoing total knee arthroplasty. Fixed flexion deformities may result from posterior capsular scarring, osteophyte formation, and bony impingement. It is essential to correct this deformity at the time of total knee arthroplasty, as a residual flexion contracture will result in joint overload and abnormal gait mechanics. This may translate to a slower walking velocity, shorter stride length, and pain. This presentation will discuss a systematic way of dealing with flexion contractures to ensure that the total knee arthroplasty will achieve full extension. The surgical technique for treating fixed flexion deformity about the knee includes release of the posterior cruciate ligament, posterior capsular release, adequate distal femoral bone resection, and removal of osteophytes. Postoperatively, attention must be divided between obtaining maximal flexion and full extension. Should a flexion contracture be noted upon the postoperative visit, additional measures should be taken to address it

Flexion contractures are a common finding in an end-stage arthritic knee, occurring in up to 60% of patients undergoing total knee arthroplasty. Fixed flexion deformities may result from posterior capsular scarring, osteophyte formation, and bony impingement. It is essential to correct this deformity at the time of total knee arthroplasty, as a residual flexion contracture will result in joint overload and abnormal gait mechanics. This may translate to a slower walking velocity, shorter stride length, and pain. This presentation will discuss a systematic way of dealing with flexion contractures to ensure that the total knee arthroplasty will achieve full extension. The surgical technique for treating fixed flexion deformity about the knee includes release of the posterior cruciate ligament, posterior capsular release, adequate distal femoral bone resection, and removal of osteophytes. Post-operatively, attention must be divided between obtaining maximal flexion and full extension. Should a flexion contracture be noted upon the post-operative visit, additional measures should be taken to address it

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

Objective: To emphasize the need to provide a controlled method of intra-operative reduction to correct fixed cervical flexion deformities in ankylosing spondylitis and to describe the technique involved. Design: The treatment of severe fixed cervical flexion deformity in ankylosing spondylitis represents a challenging problem that is traditionally managed by a corrective cervicothoracic osteotomy. The authors describe a method of controlled surgical reduction of the deformity, which eliminates saggital translation and reduces the risk of neurological injury. Subjects: 2 male patients aged 39 and 45 years old with ankylosing spondylitis presented with severe fixed flexion deformity of the cervical spine. Both patients had previously undergone a lumbar extension osteotomy to correct a severe thoracolumbar kyphotic deformity. As a result of the fixed cervical flexion deformity, marked restriction in forward gaze with ‘chin on chest’ deformity, feeding difficulties and personal hygiene were encountered in both. Their respective chin-brow to vertical angle was 60 and 72°. Somatosensory and motor evoked potentials were used throughout surgery. A combination of cervical lateral mass screws and thoracic pedicle screws were used. Interconnecting malleable rods were then fixed at the cervical end, thereby allowing them to slide through the thoracic clamps thus achieving a safe method of controlled closure of the cericothoracic osteotomy. When reduction was achieved, definitive pre-contoured titanium rods were interchanged. Halo-jacket was not considered necessary in view of the segmental fixation used. Results: Good anatomical reduction was achieved, with near complete correction of the deformities, restoration of saggital balances and forward gazes. There were no neurological deficits in either patient and the postoperative recoveries were uneventful. Both osteotomies united with no deterioration noted at 2 years. Conclusions: We illustrate a controlled method of surgical reduction during corrective cervicothoracic osteotomy of fixed cervical kyphosis in ankylosing spondylitis. This has been achieved with the use of a combination of cervical lateral mass screws and thoracic pedicle screws with interconnecting malleable rods that were later replaced with titanium rods. The authors believe that the unique technique described remains a technically demanding but adequate and safe approach for correcting such challenging deformities

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