Operative Treatment Options for Patellofemoral Arthritis: An Expert Recommendation of the AGA Patellofemoral Committee.

BACKGROUND: The operative therapy of patellofemoral arthritis requires an individual approach depending on the underlying injury. However, the literature lacks recommendations for its course of action. PURPOSE: To generate an expert recommendation of therapy for different patellofemoral abnormalities in patients suffering from isolated patellofemoral arthritis. STUDY DESIGN: Consensus statement. METHODS: To generate recommendations, the AGA Patellofemoral Committee performed a consensus process using the Delphi method based on the available literature on isolated patellofemoral arthritis. RESULTS: In most statements and recommendations, a high percentage of consensus could be found. However, also in the expert group of the AGA Patellofemoral Committee, some controversies on the treatment of patellofemoral arthritis exist. CONCLUSION: The operative therapy of isolated patellofemoral arthritis is a challenging topic that leads to controversial discussions, even in an expert group. With this consensus statement of the AGA Patellofemoral Committee, recommendations on different operative treatment options were able to be generated, which should be considered in clinical practice.

Conservative Versus Surgical Treatment for Primary Patellar Dislocation.

BACKGROUND: Primary patellar dislocation is often the initial manifestation of patellofemoral instability. Its long-term consequences can include recurrent dislocation and permanent dysfunction of the knee joint. There is no consensus on the optimal treatment of primary patellar dislocation in the relevant literature. The main prerequisite for a good long-term result is a realistic assessment of the risk of recurrent dislocation. METHODS: We carried out a systematic literature search in OvidSP (a search engine for full-text databases) and MEDLINE to identify suitable stratification models with respect to the risk of recurrent dislocation. RESULTS: In the ten studies included in the current analysis, eight risk factors for recurrence after primary patellar dislocation were identified. Six studies revealed a higher risk in younger patients, particularly those under 16 years of age. The sex of the patient had no clear influence. In two studies, bilateral instability was identified as a risk factor. Two anatomical risk factors-a high-riding patella (patella alta) and trochlear dysplasia-were found to have the greatest influence in six studies. In a metaanalysis of five studies, patella alta predisposed to recurrent dislocation with an odds ratio (OR) of 4.259 (95% confidence interval [1.9; 9.188]). Moreover, a pathologically increased tibial tuberosity to trochlear groove (TT-TG) distance and rupture of the medial patellofemoral ligament (MPFL) on the femoral side were associated with higher recurrence rates. Patients with multiple risk factors in combination had a very high risk of recurrence. CONCLUSION: The risk of recurrent dislocation after primary patellar dislocation is increased by a number of risk factors, and even more so when multiple such risk factors are present. Published stratification models enable an assessment of the individual risk profile. Patients at low risk can be managed conservatively; surgery should be considered for patients at high risk.

Successful adaption of the Banff Patella Instability Instrument (BPII) 2.0 into German.

PURPOSE: The aim of this study was to adapt, translate, and validate the Banff Patella Instability Instrument (BPII) 2.0 into German, enabling its use by German-speaking professionals for the evaluation of patients who present with patellofemoral instability. METHODS: Forward and backward translation was performed according to international recommendations. The final German version of the BPII 2.0 was investigated in patients with confirmed diagnoses of recurrent patellofemoral instability in Germany, Austria, and Switzerland. All patients received two packages of questionnaires, each containing the BPII 2.0, Kujala scoring questionnaire, Norwich Patella Instability scoring questionnaire, Short Form-36 (SF-36), and a visual analogue scale (VAS)-scale for pain and disability. The first and second packages of questionnaires were to be completed 7 days apart. The following parameters were assessed: internal consistency, test-retest reliability, floor and ceiling effects, and construct validity. RESULTS: The study population consisted of 64 patients (24 males and 40 females). The average age of the patients was 22 ± 6 years. The internal consistency (Cronbach's alpha) was excellent at both time points (0.93 and 0.95), and the test-retest reliability (ICC) was good (0.89). There were no floor or ceiling effects. There were statistically significant correlations between the BPII 2.0 and all other outcome measures apart from SF-36 mental health. CONCLUSION: The BPII 2.0 was successfully adapted into German. It is a reliable and valid instrument for evaluation of German-speaking patients who present with patellofemoral instability. LEVEL OF EVIDENCE: III.

The use of tibial tuberosity-trochlear groove indices based on joint size in lower limb evaluation.

PURPOSE: The correlation between tibial tuberosity-trochlear groove distance (TT-TG) and joint size, taking into account several different parameters of knee joint size as well as lower limb dimensions, is evaluated in order to assess whether TT-TG indices should be used in instead of absolute TT-TG values. METHODS: This study comprised a retrospective analysis of knee CT scans, including 36 cases with patellofemoral instability (PFI) and 30 controls. Besides TT-TG, five measures of knee joint size were evaluated in axial CT slices: medio-lateral femur width, antero-posterior lateral condylar height, medio-lateral width of the tibia, width of the patella and the proximal-distal joint size (TT-TE). Furthermore, the length of the femur, the tibia and the total leg length were measured in the CT scanogram. Correlation analysis of TT-TG and the other parameters was done by calculating the Spearman correlation coefficient. RESULTS: In the PFI group lateral condylar height (r = 0.370), tibia width (r = 0.406) and patella width (r = 0.366) showed significant moderate correlations (p < 0.03) with TT-TG. Furthermore, we found a significant correlation between TT-TG and tibia length (r = 0.371) and total leg length (r = 381). The control group showed no significant correlation between TT-TG and knee joint size or between TT-TG and measures of lower limb length. CONCLUSIONS: Tibial tuberosity-trochlear groove distance correlates with several parameters of knee joint size and leg length in patients with patellofemoral instability. Application of indices determining TT-TG as a ratio of joint size could be helpful in establishing the indication for medial transfer of the tibial tuberosity in patients with PFI. LEVEL OF EVIDENCE: Level III.

Guidelines for Treatment of Lateral Patella Dislocations in Skeletally Mature Patients.

The incidence of lateral patella dislocations is high, particularly in young females. Beside traumatic cases, many patients present with specific anatomical factors that predispose to lateral patella dislocations (torsional abnormalities of the femur or the tibia, trochlea dysplasia, patella alta, etc). It is of utmost importance to correct those pathologic factors during concomitant procedures as isolated reconstructions of the medial patellofemoral ligament would fail in the presence of severe anatomic risk factors. This article provides a comprehensive instruction on how to analyze the risk factors for lateral patella dislocation (anatomy, physical examination, imaging) and reports the authors' favorite surgical techniques. Moreover, treatment algorithms are provided for primary and recurrent cases of lateral patella dislocation.

The role of meniscal tissue in joint protection in early osteoarthritis.

It is widely accepted that partial meniscectomy leads to early onset of osteoarthritis (OA). A strong correlation exists between the amount and location of the resected meniscus and the development of degenerative changes in the knee. On the other hand, osteoarthritic changes of the joint alter the structural and functional integrity of meniscal tissue. These alterations might additionally compromise the limited healing capacity of the meniscus. In young, active patients without cartilage damage, meniscus therapy including partial meniscectomy, meniscus suture, and meniscus replacement has proven beneficial effects in long-term studies. Even in an early osteoarthritic milieu, there is a relevant regenerative potential of the meniscus and the surrounding cartilage. This potential should be taken into account, and meniscal surgery can be performed with the correct timing and the proper indication even in the presence of early OA.