Purpose. Investigate the functional outcome of medial patellofemoral ligament (MPFL) surgery for patella instability. Compare functional outcome of direct MPFL repair and reconstruction using hamstring graft. Methods. All patients that underwent MPFL surgery for patella instability between 2007-2010 were retrospectively identified from operative records. Patients were divided based on whether they underwent direct repair of MPFL, or reconstruction using hamstring graft. The Kujala scoring questionnaire for patellofemoral disorders (max score 100) was used to assess their functional outcome following surgery. Results. 33 patients were identified, 11 were not suitable for inclusion in the study. The remaining 22 patients had a total of 25 operations for patella stabilisation (3 bilateral). Average age of patient at time of surgery was 21 (15-33), 15 male and 7 female. 17 had direct repair of MPFL, 8 had reconstruction using hamstring graft. Of the 8 reconstructions 6 were primary procedures and 2 were for failed direct repair due to further traumatic injury. Mean follow-up period was 17 months (6-43). Mean Kujala score overall 91.6, mean score for reconstruction group 93.2, direct repair score 90.7. Total number of further patella dislocations in the repair group was 1/17 (5.9%). No patients in the reconstruction group reported any further patella dislocations following their surgery. Conclusion. Both direct repair and reconstruction of MPFL for patella instability demonstrate high functional outcome at short/mid-term follow up. Our high success rate in direct MPFL repair, good functional outcome and low re-dislocation rate is better than that quoted in the current literature

Patella instability is a common problem with many surgical options. We prospectively evaluated the results of medial patella femoral ligament (MPFL) reconstruction with an autogenous gracilis or semitendinous graft. With a minimum follow up of one year patients were reviewed using the Kujala scoring system. Twenty MPFL reconstructions were performed on seventeen patients over a two year period, from January 2004 to December 2005. There were 13 females and 4 males. Three patients had bilateral involvement. Thirteen patients had a lateral release with their MPFL reconstruction and three had a distal realignment procedure as well to correct their patella instability. The mean follow up was 17 months (range 12 to 26 months). The average age was 25 years old at operation (range 13 to 47) and the average age of their first dislocation was 16 (range 0-35). Nine patients had previous surgical treatment for patella instability. The average hypermobility score in the patients was 5/9 and six patients scored 9/9. At follow up 18 out of 20 patients (90%) had stable tracking with no further subluxations/dislocations. Of the two with unstable tracking, one had a stable patella before falling several times onto her knee. An MRI confirmed the ligament was intact but a type 2 trochlear dysplasia was present and a Bereiter trochleoplasty was subsequently performed. The other patient described no frank dislocation but instead subluxations. Eighteen of the twenty reconstructions (90%) achieved a stable patella. Overall Kujala scores increased by a third

Twenty four operations were reviewed in 23 patients to show a modified Roux-Goldthwait operation would improve the symptoms of chronic patella instability. This retrospective study used a questionnaire to record symptoms before and after surgery. The examination assessed joint hypermobility, patella tracking and stability, the Q and valgus angles of the knee. Apprehension test and assessment of patella tilt was also assessed. All patients underwent radiographic assessment. Twenty of 23 patients were improved by this procedure. Patella subluxation was reduced by 22%. Patella dislocation was reduced by 86%. The 3 unsuccessful cases had generalised joint laxity and may have been improved by the addition of a medial reefing procedure. There were no cases of tibial tuberosity numbness post operatively, patella tilt or failure of the transposed tendon. We showed that this procedure is effective, regardless of x-ray signs. We did observe a subjective increase in patellofemoral pain post operatively

Fifty-five patients were assessed with a minimum of five- year follow up. Patients in this study underwent initial conservative treatment consisting of twelve months of physio. Those patients who continued to have recurrent instability underwent surgery. Only patients without rotational abnormalities of the femur were included. Tibial rotational was assessed geriometrically, with the degree of external rotation corrected to 20 – 23°. Those patients with associated patella alta underwent a distal transfer of the patella tendon also. Assessment included range of motion, thigh girth, quads strength, effusion and a modified Lystrom knee score assessed function and pre and post-op radiographic assessment. The purpose of this paper is to report on the results of rotational osteotomy of the proximal tibia to treat patella instability. At a mean follow-up of seven years (range 5 – 8.2) 76% of knees treated for congenital dislocation of the patella with external tibial torsion, achieved good to excellent results. External tibial torsion associated with an increased “Q” angle is an important factor in recurrent dislocation of the patella. It is surgically correctable with a rotational osteotomy of the proximal tibia above the patella tendon insertion. This technique “normalizes” the extensor mechanics and produces better results than patella tendon transfer. Ninety percent of the patients were female with an average age of thirty (range fourteen to forty-five years). Prior unsuccessful surgical procedures included lateral release (sixteen) Maquet procedure (ten) Hauser (sixteen) medialization of the patella tendon (ten) semitendinosis tenodesis and patellectomy (two). Pre-operative external tibial torsion averaged 45° (range 40° – 65°) with an average rotational correction of 25°. The average pre-op “Q” angle was 27° and post-op 14°. Outcome assessment of the fifty-five knees showed twenty-six excellent, sixteen good and thirteen poor. Overall 76% were good to excellent. Outcome assessment was performed using a modified Lysholm score and the Tegner activity scale. The average pre-op score was forty and post-op seventy. Patients with less painful symptoms pre-op had significantly better outcomes. Knees that had undergone multiple unsuccessful surgical procedures had poorer outcomes

Introduction and Aims: External tibial torsion associated with an increased ‘Q’ angle is an important factor in recurrent patella instability. It is surgically correctable with a rotational osteotomy of the proximal tibia above the patella tendon insertion. This technique ‘normalises’ the extensor mechanics and produces better results than patella tendon transfer. Method: Fifty-five patients were assessed with a minimum of five-year follow-up. Patients in this study underwent initial conservative treatment consisting of l2 months of physio. Those patients who continued to have recurrent instability underwent surgery. Only patients without rotational abnormalities of the femur were included. Tibial rotation was assessed geriometrically, with the degree of external rotational corrected to 20–23 degrees. Those patients with associated patella alta, underwent a distal transfer of the patella tendon also. Assessment included range of motion, thigh girth, quads strength, effusion and a modified Lystrom knee score assessed function and pre- and post-op radiographic assessment. Results: Ninety percent of the patients were female with an average of 30 (range 14–45). Prior unsuccessful surgical procedures included lateral release (l6) Maquet procedure (l0), Hauser procedure (l6) medialisation of patella tendon (l0), semitendinosis tenodesis and patellectomy (two). Post-operative follow-up average five to 8.2 years. Pre-operative external tibial torsion averaged 45 degrees (range 40–65 degrees) with an average rotational correction of 25 degrees. The average pre-op ‘Q’ angle was 27 degrees and post-op 14 degrees. Average pre-op functional score has 40 and post-op 70 degrees. Outcome assessment of the 55 knees showed 26 excellent, 16 good and 13 poor. Overall 76% of the knee were good – excellent. Of the 16 patients with associated anterior knee pain, 13 obtained good-excellent results. Patients with less painful symptoms pre-op, had significantly better outcomes. Knees that had undergone multiple unsuccessful surgical procedures, had significantly poorer outcomes. Uniplanar patella tendon transfer in these cases generally results in continued anterior knee pain. Conclusions: Derotational osteotomy re-aligned the extensor mechanism in cases of recurrent dislocation of the patella secondary to external tibial torsion. All patients had some improvement with the surgery, but the patients with poor outcomes continued to have anterior knee pain

We present 10–15 year follow-up of 33 patients who underwent Elmslie-Trillat osteotomy for severe patellar subluxation or dislocation. In the literature it has been reported that tibial tubercle osteotomy predisposes to subsequent patella-femoral arthritis, however it has never been documented if pre-existent knee chondral damage has any role in this development. In our group all patients had pre-op knee arthroscopy performed and extant of chondral damage was documented. We preformed an evaluation by long-term follow-up to determine weather pre-op chondral damage was the cause of subsequent osteoarthritis of patella-femoral joint. All patients were invited to attend outpatient clinic for clinical examination and knee radiographs and assessed by an independent research surgeon. Mean age at follow-up was 43 years and average follow-up was 10.5 years (range 10–15 years). 90% follow-up was achieved. Knee function was assessed by clinical scores (Lysholm knee score, American Knee Score, Oxford Knee score, Tegner and Insall knee scores) and three radiographs (AP, Lateral and Merchant views). Four patients had developed significant arthritis and underwent joint arthroplasty. Majority of patients reported good results with no further dislocation. However we noticed that extant of pre-op chondral damage was a significant factor in subsequent development of patella-femoral arthritis. We will present our data which is unique as no previous such long-term results have been reported for tibial tubercle transfers followed-up for more than 10 years and have pre-op arthroscopic documented chondral damage.

Recognized anatomic variations that lead to patella instability include patella alta and trochlea dysplasia. Lateralization of the extensor mechanism relative to the trochlea is often considered to be a contributing factor; however, controversy remains as to the degree this contributes to instability and how this should be measured. As the tibial tuberosity-trochlear groove (TT-TG) is one of most common imaging measurements to assess lateralization of the extensor mechanism, it is important to understand its strengths and weaknesses. Care needs to be taken while interpreting the TT-TG value as it is affected by many factors. Medializing tibial tubercle osteotomy is sometimes used to correct the TT-TG, but may not truly address the underlying anatomical problem. This review set out to determine whether the TT-TG distance sufficiently summarizes the pathoanatomy, and if this assists with planning of surgery in patellar instability. Cite this article: Bone Jt Open 2022;3(3):268–274

Patellar dislocation is a common presentation with a clear management pathway. Sometimes, however, what a patient experiences as the patella dislocating may, in fact, be ACL insufficiency. We reviewed case notes and imaging of 315 consecutive ACL reconstructions, collecting data on the date and mechanism of injury, time to MRI, and reconstruction. We noted cases initially diagnosed as patellar dislocation. 25 of 315 (7.9%) patients were initially diagnosed with a patellar dislocation. Subsequently, however, MRI scans revealed no evidence of patellar dislocation and instead showed ACL rupture with pathognomonic pivot-shift bony oedema. The false patella dislocation group were 32% female and had an average age of 25; the rest of the group average age was 27.1 and there were a lower proportion of females; 21%. The false patella instability patients had a median waiting time of 412 days from injury to operation (range: 70-2445 days), compared to 392 days (range: 9 – 4212 days) for rest of the patients. 5 of the remaining 290 had MRIs showing patella oedema with medial patello-femoral ligament injury in addition to their ACL rupture. From our literature search this is a new finding which shows that ACL rupture can present with symptoms suggestive of patellar dislocation. These findings raise the risk that there are a group of people who have been diagnosed with patellar instability who instead have ACL insufficiency and so are at risk of meniscal and chondral damage. Further research should analyse those diagnosed with patellar instability to quantify missed ACL injuries

Introduction. Trochleoplasty is an effective surgical procedure for patients with severe trochlear dysplasia and recurrent patella instability. Previous work has suggested patients demonstrate early improvements in knee function and quality of life. However, concerns regarding longer term outcomes due to the development of stiffness and patellofemoral osteoarthritis remain a concern for these patients. Our aim was to assess mid-term patient-reported outcome and quality of life measures for trochleoplasty performed at a single centre for severe trochlear dysplasia. Methods. Retrospective review of 28 knees (23 patients) having undergone trochleoplasty for severe trochlear dysplasia were reviewed. Due to the non-parametric nature of the data, median and interquartile range (IQR) were determined for pre-operative and mid-term follow-up scores. Statistically significant differences between groups were assessed using paired Wilcoxon-signed rank test with statistical significance set at p<0.05. Data were analysed using a statistical software package (IBM® SPSS® Statistics 26.0). Results. Median time from surgery to follow-up for all patients in the series was 5.3 years (IQR 3.9 – 7.0 years). Median pre-operative Kujala score improved from 57.0 (IQR 45 – 66) to 96.3 (IQR 83 -100). Median pre-operative IKDC score improved from 42.6 (IQR 35.9 – 51.3) to 92.6 (IQR 71.6 – 98.7). Median EQ-5D score also improved from 0.691 (IQR 0.414 – 0.727) to 1.000 (IQR 0.8178 – 1.000). Improvement in Kujala scores, IKDC scores and EQ-5D were all statistically significant with p<0.001 in all domains. Discussion. Our data suggests patients experience significant improvements in knee function and quality of life following trochleoplasty surgery for severe dysplasia. We demonstrate an absolute improvement in scores at a mean of 5.3 years follow-up of 39.3 points for Kujala, 50 for IKDC and 0.309 for EQ-5D. Minimal clinically important differences (MCID) have been reported to be in the region of 10 for the Kujala score, 8.8–15.6 for IKDC and 0.085 for EQ-5D. Our data shows improvements which far exceed the published MCID, suggesting trochleoplasty confers a large treatment effect and patients benefiting from sustained improvements in knee function and overall quality of life at mid-term follow-up. Conclusion. Following trochleoplasty for severe trochlear dysplasia, patient reported outcomes demonstrate continued improvements in knee function and quality of life at mid-term (5-year) follow-up. There is a large absolute treatment effect which likely impacts on both physical and psychological wellbeing for these patients. Continued surveillance of patient reported outcomes in this clinically complex cohort is indicated

Purpose: Trochlea dysplasia is a developmental condition characterized by an abnormally flat or dome shaped trochlea. This predisposes to recurrent patella instability. This study prospectively reviews the early results of patients undergoing a trochleoplasty procedure which corrects the dysplastic anatomical abnormality. Patients and Methods: All patients were recruited from the senior author’s (JDJE) specialist knee clinic following the standard patellofemoral assessment. Patients were seen pre-operatively to collect epidemiological data, ensure completion of patient reported assessment forms and document clinical examination findings and investigations. Duration of instability and previous procedures performed for patella instability were recorded. Multiple patient-reported outcome measures were recorded. Outcome score assessments and clinical examinations were repeated post-operatively, along with a patient satisfaction questionnaire. All operations were carried out by the senior author with supplementary procedures based on pre-operative assessment. Results: 22 patients had a minimum of 12 months follow-up. The average age was 21 years and the average duration of instability symptoms (pre-trochleoplasty) was 7 years. There were 16 females and 6 males. Mean follow up was 18 months. Patients reported improvement in outcome when the pre and post-operative scores were compared (mean scores of Oxford 34 to 41, WOMAC 23 to 15, Kujula 62 to 79, IKDC 62 to 81, and Lysholm 57 to 77). The patient satisfaction questionnaire revealed just one patient not satisfied with the procedure despite good patient reported outcome scores. The majority of patients perceived improvement due to the surgery and agreed they would recommend the procedure to others despite some residual symptoms. Recurrent instability after trochleoplasty was rare (one subluxation) and range of movement was uniformly excellent. Conclusion: Early results of this trochleoplasty for patients with trochlea dysplasia and symptomatic recurrent patella instability are encouraging

Purpose of the study. To determine the outcome after the Semi-tendinosis tendon was used in reconstruction of the Medial Patella-femoral ligament using a fixed dynamic stabilising structure. Method. The Adductor Magnus tendon insertion at the Adductor tubercle of the medial femoral condyle was used as a dynamic and fixed stabilising point preventing patella subluxation. This is a constant landmark in most patients and eliminates the need to find the isometric stabilisation point of the Medial Patella-femoral ligament. The Semi-tendinosus tendon was routed from its distal tibia attachment through a drill hole in the patella from distal to proximal. It was then transferred sub-vastus around the Adductor Magnus femoral attachment and sutured back onto itself at the inferior patella pole. It was tensioned at 30 degrees of knee flexion. Between 2004 and 2011 forty knees were reconstructed using the Semi-tendinosus tendon combined with an extra-synovial lateral release. All had failed conservative therapy for repeated patella instability. Post-operatively the patients followed a strict rehabilitation protocol. At follow-up the patients were questioned for any symptoms of patella instability or dislocation. Any complications of the surgery were documented. Patients were examined for any signs of patella apprehension or abnormal patella tracking. Results. The male to female ratio was 2:3. The mean age was 26 (range13 to 33). The mean follow- up was 44 months. To date no recurrence of instability was noted. Within as early as 4 weeks post-surgery a reduction of patella apprehension was noted in all patients. 90% of patients were able to return to an active life-style. No serious complications were documented. Conclusion. Transferring Semi-tendinosus around the fixed, dynamic distal insertion point of Adductor Magnus provides good results in the medium term and is a technique that may be combined with distal patella tendon realignment procedures. NO DISCLOSURES

Introduction: Traditionally adolescent anterior knee pain is considered to be a self limiting condition with no long term sequelae. However recently two publications have suggested the condition may be longer lasting. We wish to suggest that adolescent anterior knee pain may lead to patello femoral arthritis. Method: We have carried out a comparative study assessing the incidence of previous adolescent anterior knee in patients who underwent patello femoral replacement for isolated patello femoral arthritis and have compared them with a matched group of patients who had medial unicompartmental replacement for isolated medial compartment arthritis without patello femoral disease. All patients were sent a postal questionnaire enquiring about adolescent anterior knee pain, knee injury and patella instability. Results: Ninety-three PFR patients and 86 UKR patients replied. The incidence of adolescent AKF and patella instability was higher in the PFR.group. Conclusion: Adolescent anterior knee pain may not always be a benign self limiting condition since this as well as patella injury and instability was associated with subsequent isolated patello femoral arthritis

The aim of this study is to document the outcome of a large cohort of patients treated with the Bereiter trochleoplasty with between 1 and 12 years of follow up. 215 consecutive cases in 186 patients were recorded prospectively. All patients were offered yearly clinical and radiological review. PROMs were recorded including the IKDC, OKS, Kujala and SF-12. Patients unable to attend clinic were assessed with PROMS and radiographs from their local institutions where possible. There were 133 females and 53 males, with a mean age of 21 (14–38). There were no infections and only 6 patients reported further dislocations. There was one flap breakdown and no identified cases of secondary osteoarthritis. PROMs were available for 194 cases in 167 patients (90% follow up). 84% of patients were satisfied, 87% felt their symptoms had improved and 69% had gone back to sport. All scores improved (all p<0.001) except for the SF-12 mental score (p=0.42), with averages comparable to the results of MPFL reconstruction. Good outcomes were observed despite the difficult patient population in which these cases were performed. The Bereiter trochleoplasty is an effective method of treating recurrent patella instability in patients with severe trochlea dysplasia

Patients with recurrent patella instability, who have an abnormal patellofemoral alignment (patella height or tibial tubercle-trochlear groove (TTTG) distance), benefit from tibial tubercle transfer along with medial patellofemoral ligament (MPFL) reconstruction. Between July 2008 and April 2013, 18 patients (21 knees) with recurrent patellar instability underwent combined MPFL reconstruction and tibial tubercle transfer. All patients had abnormal patellofemoral alignment in addition to MPFL insufficiency. 15 patients (16 knees) with a mean age of 24 years (16–41) had a mean follow up of 26 months (6–55). We assessed the outcome using KOOS, KUJALA, activity level and patient satisfaction scores. All patients had a stable patella. There was a significant improvement in outcome scores in 12 out of 15 patients. At final follow up KOOS score had improved from 68.25(44 to 93.9) to 77.05(48.8 to 96.4) and KUJALA score had improved from 63.3(41–88) to 78.06 (45 to 99). 9 patients showed excellent results and achieved at least a pre-injury level of activity. 4 of these had activity level better then preoperative level. 6 patients had a lower activity level than pre-injury (1 – ongoing physiotherapy, 1 – because of lack of confidence, and 4 – Life style modification). 14 patients were satisfied and happy to recommend this procedure. There were 3 postop complications, with 2 cases of stiffness and 1 case of non-union of the tibial tuberosity. Our prospective study has shown that restoration of tibial tubercle-trochlear groove index, Patella height and Medial Patellofemoral Ligament reconstruction yields good results in carefully selected patients

Aims

The aim of this study was to evaluate medium- to long-term outcomes and complications of the Stanmore Modular Individualised Lower Extremity System (SMILES) rotating hinge implant in revision total knee arthroplasty (rTKA) at a tertiary unit. It is hypothesized that this fully cemented construct leads to satisfactory clinical outcomes.

Aims

During total knee replacement (TKR), surgeons can choose whether or not to resurface the patella, with advantages and disadvantages of each approach. Recently, the National Institute for Health and Care Excellence (NICE) recommended always resurfacing the patella, rather than never doing so. NICE found insufficient evidence on selective resurfacing (surgeon’s decision based on intraoperative findings and symptoms) to make recommendations. If effective, selective resurfacing could result in optimal individualized patient care. This protocol describes a randomized controlled trial to evaluate the clinical and cost-effectiveness of primary TKR with always patellar resurfacing compared to selective patellar resurfacing.

Introduction. The dysplastic trochlear is a developmental condition characterized by an abnormally flat or dome-shaped trochlea and it is recognized as a significant cause of patella instability. Surgical correction of the shape of the Trochlear Groove is frequently performed. The described methods in the literature involve open arthrotomy to normalize and maintain the trochlear morphology achieving normal alignment and tracking of the patella. Material, methods and results. Open procedures carries a significant risk of arthrofibrosis. We describe an arthroscopic procedure to create a neo-trochlea using gouges, spherical and conical hooded burrs. We studied prospectively a series of 4 consecutive patients with patello-femoral instability secondary to trochlear dysplasia, who were treated by an Arthroscopic trochleoplasty by a single surgeon between 2007 and 2008. Postoperatively the patients were rehabilitated in accordance with our routine Patello-Femoral microfracture protocol. CT scanning at one year showed a complete neo-cortex and cartilage sequenced MRI at 12 months showed complete fill with fibro cartilage. Pre- and post-operative scores (KOOS, Kujala) were assessed by the patients and a satisfaction questionnaire was completed. The results showed a statistical improvement in the outcome at the 3 year follow up. Conclusion. Overall, patients (100%) were satisfied with the outcome of their procedure and there have been no adverse events. To our knowledge this technique has not been described before in the English literature and the early results of arthroscopic trochleoplasty are encouraging and offer an alternative to open approaches. Larger numbers and longer follow ups are needed to confirm the long term benefit

Patella recurrent dislocation and patellofemoral pain syndrome instability many young people and especially athletes. In the present study we present the results of the extension mechanism realignment through the Fulkerson oblique osteotomy of the tibial tuberosity and soft tissue balancing. During the last two years 10 patients (7 men, 3 women, mean age 29.3/ range 20–39) were treated operatively for recurrent dislocation of the patella using the Fulkerson procedure. All patients underwent knee arthroscopy for the treatment of potential chondral damage or loose bodies and for lateral retinacular release. After that we performed oblique tibial tuberosity osteotomy, medialization and internal fixation with 2 cortical screws. This oblique osteotomy allows also the anteriorization of tibial tuberosity as we move it medially. In addition, we performed medial placation. All the patients used functional knee brace locked to 0° right after the operation and with gradual ROM increase till the 8th p.o. week. The patients had no initial or long term complication. During their last follow up examination had a painless knee with full ROM and marked improvement of the patella tracking. The mean Lysholm score was 90.5. No patella dislocation was referred. Our findings show that the Fulkerson osteotomy procedure, with an additional intervention on the lateral and medial patella retinacular, is an excellent option for the treatment of recurrent patella instability and relief of the patellofemoral pain

The dysplastic Trochlear is a developmental condition characterised by an abnormally flat or dome-shaped trochlea and it is recognised as a significant cause of patella instability, with the increased sulcus angle being is the most common finding. Surgical correction of the shape of the Trochlear Groove is frequently performed. The described methods in the literature involve open arthrotomy to normalise and maintain the trochlear morphology achieving normal alignment and tracking of the patella. Open procedures carries a significant risk of arthrofibrosis. The technique was developed in human cadaveric knees at the Donjoy Clinical Education and Research Facility (CERF) in Vista California. We describe an arthroscopic procedure to create a neo-trochlea using gouges, spherical and conical hooded burrs. We studied prospectively a series of 4 consecutive patients with patello-femoral instability secondary to trochlear dysplasia, who were treated by an Arthroscopic trochleoplasty by a single surgeon between 2007 and 2008. Postoperatively the patients were rehabilitated in accordance with our routine Patello-Femoral microfracture Protocol, allowing weight bearing and ROM 0-20 degrees in a long lever brace for 6 weeks. CT scanning at one year showed a complete neo-cortex and cartilage sequenced MRI at 12 months showed complete fill with fibro cartilage. Pre- and post-operative scores (KOOS, Kujala) were assessed by the patients and a satisfaction questionnaire was completed. The results showed a statistical improvement in the outcome at the 2 year follow up. Overall, patients (100%) were satisfied with the outcome of their procedure and there have been no adverse events. To our knowledge this technique has not been described before in the English literature and the early results of arthroscopic trochleoplasty are encouraging and offer an alternative to open approaches. Larger numbers and longer follow ups are needed to confirm the long term benefit

Purpose: Mal-tracking or dislocation of the patella is often the result of abnormal anatomy. Understanding the anatomy will clarify the treatment options available. The common anatomical causes of dislocation range from the valgus knee to patella alta and external tibial torsion. External tibial torsion results in symptoms ranging from patello-femoral pain to subluzation or dislocation. Many patients become symptomatic after an injury and recognition of the anatomical pathology helps in the treatment decision. Method: A retrospective study was carried out on 232 rotational high tibial osteotomies in 221 patients operated on between 1990–2004. The pre-operative degree of external tibial torsion and ‘Q’ angle was noted. The extent of any patello-femoral pathology was documented, as well as the degree of correction. Assessment was carried out using the HSS score and the Lysholm score. Notation was made of prior surgery, including arthroscopy, patella tendon tarnsfer and patellectomy. Results: Of the 232 cases, 80% showed good to excellent results with resolution of patello-femoral pain and instability. Ten percent had residual pain but no instability and 20 cases proceeded to total knee replacement. The best results were seen in cases of pain and instability with minimal patello-femoral arthritis. Some cases with end-stage patello-femoral arthritis were improved with the improvement in quadriceps function via reduction in the ‘Q’ angle. Conclusion: Rotational osteotomy of the proximal tibia for symptomatic patella instability secondary to significant external tibial torsion results in good to excellent results in 80% of cases