Aims

Classifying trochlear dysplasia (TD) is useful to determine the treatment options for patients suffering from patellofemoral instability (PFI). There is no consensus on which classification system is more reliable and reproducible for the purpose of guiding clinicians’ management of PFI. There are also concerns about the validity of the Dejour Classification (DJC), which is the most widely used classification for TD, having only a fair reliability score. The Oswestry-Bristol Classification (OBC) is a recently proposed system of classification of TD, and the authors report a fair-to-good interobserver agreement and good-to-excellent intraobserver agreement in the assessment of TD. The aim of this study was to compare the reliability and reproducibility of these two classifications.

A number of measurements of patellar height are in clinical use all of which reference from the tibia. The patellotrochlear index has been proposed recently as a more accurate reflection of the functional height of the patella and described in normal knees. We compared patellar height measurements in patients with patellofemoral dysplasia. In a retrospective analysis of the MRI scans of 33 knees in 29 patients with patellofemoral dysplasia we assessed the inter- and intraobserver reliability of four patellar height measurements: the recently described Patellotrochlear Index (PTI), Insall-Salvati (IS), Blackburne-Peel (BP) and Caton-Deschamps (CD) ratios. We also assessed the correlation between the different measurements in predicting patella alta. Three blinded observers on two separate occasions performed the measurements. There were 21 females and 8 males with a mean age of 21.4 years (13–33). Statistical analysis revealed good inter-observer reliability for all measurements (0.78 for PTI, 0.78 for IS, 0.73 for BP and 0.77 for CD). Intra-observer reliability was also good (0.80, 0.83, 0.75, 0.78 respectively). There was weak correlation between the PTI and the other ratios for patella alta. There was a strong correlation between the CD and BP ratios (0.96) and a moderate correlation between IS and CD and IS and BP ratios (0.594 and 0.539 respectively). We propose the PTI as a more clinically relevant measure

A number of measurements of patella height exist all of which use a position on the tibia as a reference. The Patellotrochlear Index has recently been proposed as a more accurate reflection of the functional height of the patella and described in normal knees. We aimed to compare patellar height measurements in patients with patellofemoral dysplasia. In a retrospective analysis of the MRI scans of 33 knees in 29 patients with patellofemoral dysplasia we assessed the inter- and intraobserver reliability of four patellar height measurements: the Patellotrochlear Index (PTI), Insall-Salvati (IS), Blackburne-Peel (BP) and Caton-Deschamps (CD) ratios. We also assessed the correlation between the different measurements in predicting patella alta. Three blinded observers on two separate occasions performed the measurements. There were 21 females and 8 males with a mean age of 21.4 years (13–33). Statistical analysis revealed good inter-observer reliability for all measurements (0.78 for PTI, 0.78 for IS, 0.73 for BP and 0.77 for CD). Intra-observer reliability was also good (0.80, 0.83, 0.75, 0.78 respectively). When comparing the different measurements for patella alta there was a weak correlation between the PTI and the others. There was a strong correlation between the CD and BP ratios (0.96) and a moderate correlation between IS and CD and IS and BP ratios (0.594 and 0.539 respectively). All measurements are reproducible. The PTI however suggests patella alta exists in different patients to that suggested by the established measures. We propose the PTI as a more clinically relevant measure

A number of measurements of patella height exist all of which use a position on the tibia as a reference. The Patellotrochlear Index has recently been proposed as a more accurate reflection of the functional height of the patella and described in normal knees. Aim: A comparison of patellar height measurements in patients with patellofemoral dysplasia. Method: A retrospective analysis of the MRI scans of 33 knees in 29 patients with patellofemoral dysplasia to assess the inter- and intraobserver reliability of four patellar height measurements: the Patellotrochlear Index (PTI), Insall-Salvati (IS), Blackburne-Peel (BP) and Caton-Deschamps (CD) ratios. We also assessed the correlation between the different measurements in predicting patella alta. Three blinded observers on two separate occasions performed the measurements. Results: There were 21 females and 8 males with a mean age of 21.4 years (13–33). Statistical analysis revealed good inter-observer reliability for all measurements (0.78 for PTI, 0.78 for IS, 0.73 for BP and 0.77 for CD). Intra-observer reliability was also good (0.80, 0.83, 0.75, 0.78 respectively). When comparing the different measurements for patella alta there was a weak correlation between the PTI and the others. There was a strong correlation between the CD and BP ratios (0.96) and a moderate correlation between IS and CD and IS and BP ratios (0.594 and 0.539 respectively). Conclusion: All measurements are reproducible. The PTI however suggests patella alta exists in different patients to that suggested by the established measures. We propose the PTI as a more clinically relevant measure

Despite the successful, durable results, concern remains for using TKA in patients with isolated patello-femoral OA, as it requires an extensive surgical exposure and bone resection, a long recovery time, and a potentially more complex revision than that required for a patient with a failed patello-femoral arthroplasty (PFA). PFA was introduced in the late 1970s. While PFA was successful in providing pain relief, the procedure did not gain widespread use because of initial design limitations that predisposed to PF maltracking, catching, and subluxation. The mechanical complications associated with first-generation PFA offset the potential advantages of maintaining the knee's native soft tissues and spurred efforts to improve implant design, and to refine surgical techniques and patient selection. Over the past two decades, second generation PFAs incorporated changes in implant design and instrumentation and have shown promising results when used in the properly selected patient population. In addition, with improved instrumentation and robotics, adequate implant alignment and rotation can be achieved in the majority of patients, including those with severe patellofemoral dysplasia. Our meta-analysis of TKA and PFA for the treatment of isolated patello-femoral OA showed that the rate of complications of patients undergoing PFA was 30% after a median follow up of 5.3 years, which is significantly higher than the 7% rate of complications in patients who underwent TKA. The most frequent type of complication associated with PFA was mechanical (including loosening and instability), which is consistent with the malalignment and maltracking-related failures previously reported. The incidence of re-operation after PFA (21%) was significantly higher than that seen after TKA (2%). The most frequent indication for re-operation after PFA was mechanical failure (7%), followed by progression of OA (6%), and persistent pain or stiffness (5%). The most common re-operations after PFA were conversion to TKA, revision of PFA components, lateral releases, open or arthroscopic debridement, manipulations under anesthesia, and bony and/or soft tissue extensor mechanism re-alignment procedures. In our study, 11% of patients treated with PFA underwent a revision arthroplasty, with 4% undergoing revision PFA and 7% undergoing conversion to TKA. Our comparison of patients who were treated with second-generation PFA designs versus TKA showed no difference in the rate of complications, re-operation, or revision arthroplasty. Additionally, length of follow-up did not significantly influence any of these outcomes when comparing second-generation PFA and TKA. These observations provide support for the use of current PFA designs. The mechanical complications and subsequent re-operations that affected first-generation PFA designs appear to be of less concern with proper patient selection, meticulous surgical technique, current implant designs and peri-operative care. While it is difficult to predict the survivorship of current PFA designs, it is our expectation that patient selection will continue to be a critical component in determining long-term results. The potential benefit of providing pain relief while preserving the tibiofemoral articulations makes PFA a promising treatment option

Aims: The purpose of the study was to assess the mid-term knee functional results after Medial Patellofemoral Ligament (MPFL) reconstruction with single semitendinosus autograft in patients with patellofemoral instability. Methods and Results: Knee function was assessed in 45 patients (46 knees) who underwent MPFL reconstruction with semitendinosus autograft. The tibial insertion of the semitendinosus was preserved whereas the free end, after stripping of the tendon from the musculo-tendinus junction was rerouted through the most distal part of the medial intermuscular septum proximally to the adductor tubercle, to the superomedial border of the patella, where it was fixed. Clinical and radiological evidence of patellar instability and MPFL rupture or deficiency was documented prior to surgery. Knee function was assessed preoperatively and postoperatively with the use of Kujala, Tegner, Lysholm and International Knee Documentation Committee (IKDC) scores. There were 34 male and 11 female patients with an average age of 32.5 years, ranging from 17 to 60 years. The minimum follow up was 2 years with an average of 33.5 months (range 24–54 months). Fourteen patients (30%) presented a degree of patellofemoral dysplasia. All knee functional scores significantly improved postoperatively. Kujala score improved from 57.7 to 77.1, Tegner score improved from 3.06 to 5.26, IKDC score improved from 51.2 to 75.44 and Lysholm score improved from 58.7 to 79.3. One of the patients required revision of the MPFL reconstruction due to traumatic redislocation of the patella. Conclusions: At a midterm follow-up, reconstruction of the MPFL with rerouting of the semitendinosus tendon is an effective method with improved function in all patients. Maximum improvement was achieved within the first six postoperative months. Heterogeneity of our population may have affected some of our results

Background: Isolated patellofemoral arthroplasty has gained new attention after recently published positive results. It is considered an intermediate treatment for the patient with isolated arthritis of the anterior compartment of the knee. Aim of this nationwide survey was to determine the current status of patellofemoral arthroplasty in Germany. Methods: All German departments of orthopaedic surgery, traumatology and general surgery with a yearly performance of at least fifty knee arthroplasties were asked to complete a standardized questionnaire. In the first part, surgeons were asked general questions about their department size, case numbers of knee arthroplasties per year and non-endoprosthetic treatment of isolated patellofemoral disorders. If patellofemoral arthroplasty was conducted, parameters concerning age, gender, duration of complaints, indication for surgery, surgical approach, type of endoprosthesis used, additional surgical treatments and failures were evaluated in the second part. Furthermore we asked for the reasons if no isolated patellofemoral arthroplasty was performed. Results: A total of 224 (30%) usable questionnaires were returned. Of 53420 knee arthroplasties performed per year, only 195 were isolated patellofemoral arthroplaties (0.37%). However, in 54 departments (24%), at least one isolated patellofemoral arthroplasty was performed with an average of 3.95 (1–20) procedures per year. The majority of patients were between 40 and 60 years old (40–60y: 56%; 20–40y: 8%, 60–80y: 35%, > 80y: 1%). Females were affected in 65% of patients. Etiology of isolated patellofemoral arthritis was believed to be idiopathic in 41% and traumatic in 8%. Patellofemoral dysplasia was held responsible in 47% and patellofemoral instability in 4% of cases. The main reason for failure and surgical revision was ongoing pain of the affected knee (40%). Negative attitude and disbelief towards the success of isolated patellofemoral arthroplasty were stated by the majority (62%) of non-users. A lack of appropriate indications was reported by 22% and missing know-how by 16%. Conclusions: Isolated patellofemoral arthroplasty has only little significance among surgeons performing knee arthroplasty in Germany. Although promising results were reported in the literature, the majority of surgeons do not believe in the success of the procedure

Aim: To evaluate the repair of articular cartilage defects in the knee treated by autologous chondrocyte implantation (ACI), using arthroscopic assessment. Method: One hundred and six articular cartilage defects in 79 knees of 77 patients were treated by ACI. The chondrocytes were injected beneath a periosteal flap (Brittberg et al, 1994). Arthroscopy and removal of the metal implants were performed nine months following implantation. The ICRS score was used to assess the repairs. Results: Of the 79 knees 43.5% of the lesions involved the patella, 35.2% the femoral condyles, 16.7% the trochlea, and 4.6% the tibial condyles. The average defect size was 254.65mm. 2. It was found that 20% of knees had more than one defect. Associated biomechanical procedures were carried out in 88.7%. Seventy lesions in 58 knees (56 patients) have been assessed; four eligible patients were not assessed arthroscopically. The ICRS scores (maximum 12) were: tibial condyle 11.5; patella 11.3; femoral condyle 11.0, and trochlea 10.7. Synovitis was markedly reduced in all knees with well-healed defects. Adhesions between the periosteal graft and the synovium caused a click in 11 patients, which was relieved by arthroscopic resection. Incomplete healing occurred in one patient with a wound dehiscence, in two following a fall in the post-operative period, and in one patient with a non-contained defect. Biopsies at arthroscopy showed predominantly hyaline cartilage. Conclusions: We concluded that ACI was an effective method of repairing articular cartilage defects. In this series the results for the patella matched those for the femoral condyle, attributed to the simultaneous biomechanical correction of patellofemoral dysplasia. Stabilisation of the articular surface resulted in resolution of synovitis

The June 2012 Children’s orthopaedics Roundup³⁶⁰ looks at; open reduction for DDH; growing rod instrumentation for scoliosis; acute patellar dislocation; management of the relapsed clubfoot; clubfoot in Iran; laughing gas and fracture manipulation; vascularised periosteal fibular grafting for nonunion; slipped upper femoral epiphysis; intramedullary leg lengthening and orthopaedic imaging and defensive medicine.