Trohleoplastika: Kirurške indikacije i operacijska tehnika u liječenju rekurentne patelarne dislokacije pri uznapredovaloj patelofemoralnoj displaziji

Trochleoplasty is a surgical procedure which was initially reserved for the refractory cases where previous surgery has failed, but has become more popular in the past years because of a better knowledge of the knee anatomy and biomechanics and a greater availability of surgical instruments. The technical difficulty of the sulcus-deepening trochleoplasty lies in the fact that surgeons aim to reshape a usually extremely dysplastic articular surface of the trochlea without damaging it. If patients are carefully selected and the surgical rationale is carefully followed, recent bibliography presents very encouraging results of the application of trochleoplasty with other procedures in patients with severe trochlear dysplasia and recurrent patellar dislocation, in whom benign neglect of dysplasia would lead to unfavourable results. The surgical steps and technical pearls of the procedure are described in this review.Trohleoplastika je kirurški zahvat koji se koristi u liječenju rekurentnih dislokacija patele kod displazija patelofemoralnog zgloba. U početku se trohleoplastika primjenjivala samo kod pacijenata kod kojih ostale metode nisu polučile uspjeh. Kako saznanja o anatomiji i biomehanici napreduju, kao i tehnološka dostignuća u konstruiranju kirurških instrumenata, tako raste i popularnost takve vrste kirurškog zahvata raste. Radi se o zahtjevnom kirurškom zahvatu kod kojeg je potrebno preoblikovati displastično promijenjenu trohleu femura, a da se pritom značajno ne ošteti zglobna hrskavica. Noviji rezultati u pacijenata s visokim stupnjem displazije trohlee femura i rekurentnim dislokacijama patele, govore u prilog trohleoplastike u usporedbi s ostalim kirurškim postupcima. Ovaj rad u detalje opisuje kiruršku tehniku trohleoplastike

Tibial tubercle osteotomy in patello-femoral instability and in patellar height abnormality

The aim of this study was to present the different surgical procedures of tibial tubercle osteotomies for patellar instability or patellar mispositioning such as patella alta or patella infera. This study analysed the Caton–Deschamps index used for assessment of vertical patella height in order to make a precise plan for tibial tuberosity osteotomies. This study included 61 knees (50 patients) treated for patellar instability with patella alta and 24 patients treated for patella infera of mechanical origin. The results of medial transfer of the tibial tuberosity, with or without distal transfer in cases of patellar instability with patella alta, gives excellent results for stability in 76.8% of the cases. The results of the proximal transfer of the tibial tuberosity in cases of patella infera were excellent or good in 80% of the cases in our series of 24 patients. A precise preoperative plan is needed with determination of the vertical patellar height using the Caton–Deschamps index and the situation of the tibial tuberosity and the Tibial Tubercle to Trochlear Groove distance (TT-TG) of the knee on CT scan in order to obtain satisfactory results

A non‐weight bearing protocol after ACL reconstruction improves static anterior tibial translation in patients with elevated slope and increased weight bearing tibial anterior translation

Abstract Purpose Aim of this study is to evaluate the impact of a non‐weight bearing (NWB) protocol within 21 post‐operative days after anterior cruciate ligament (ACL) reconstruction on static and dynamic anterior tibial translations (SATT and DATT, respectively). The hypothesis is that delayed WB would improve ATT at 9 months follow‐up. Methods A series of patients treated with ACL reconstruction was retrospectively reviewed, comparing a group with immediate post‐operative weight bearing (WB group) and a group without post‐operative weight bearing (NWB group). The NWB protocol was applied to patients with posterior tibial slope (PTS) ≥ 12°, pre‐operative SATT ≥ 5 mm, and/or meniscal lesions of root or radial type. SATT, and PTS were measured on 20° flexion monopodal lateral x‐rays, while DATT on Telos™ x‐rays at pre‐operative and 9‐months follow‐up. Results One hundred seventy‐nine patients were included (50 NWB group, 129 WB group). The SATT worsened in the WB group with a mean increase of 0.7 mm (SD 3.1 mm), while in the NWB group, the SATT improved with a mean decrease of 1.4 mm (SD 3.1 mm) from the pre‐operative to 9 months’ follow‐up (p < 0.001). The side‐to‐side Telos™ evaluation showed a significant improvement in DATT within both the groups (p < 0.001), but there was no difference between the two groups (p = 0.99). Conclusion The post‐operative protocol of 21 days without WB led to an improvement in SATT at 9 months without an influence on DATT, and it is recommended for patients with a SATT ≥ 5 mm and/or a PTS ≥ 12° as part of an “à la carte” approach to ACL reconstruction. Level of evidence Level IV, Retrospective case serie

Patellofemoral anatomy and biomechanics: current concepts

The patellofemoral joint, due to its particular bone anatomy and the numerous capsuloligamentous structures and muscles that act dynamically on the patella, is considered one of the most complex joints in the human body from the biomechanical point of view. The medial patellofemoral ligament (MPFL) has been demonstrated to contribute 60% of the force that opposes lateral displacement of the patella, and MPFL injury results in an approximately 50% reduction in the force needed to dislocate the patella laterally with the knee extended. For this reason, recent years have seen a growing interest in the study of this important anatomical structure, whose aponeurotic nature has thus been demonstrated. The MPFL acts as a restraint during motion, playing an active role under conditions of laterally applied stress, but an only marginal role during natural knee flexion. However, it remains extremely difficult to clearly define the anatomy of the MPFL and its relationships with other anatomical structures

Association of trochlear dysplasia with degenerative abnormalities in the knee: data from the Osteoarthritis Initiative

OBJECTIVE: To evaluate trochlear morphology as a potential risk factor for patellofemoral osteoarthritis, determined by morphological and quantitative measurements of cartilage degeneration using 3T magnetic resonance imaging (MRI) of the knee. MATERIALS AND METHODS: MR images of right knees of 304 randomly selected subjects, aged 45–60 years, from the Osteoarthritis Initiative (OAI) progression cohort were screened for trochlear dysplasia, defined by an abnormal trochlear depth. Out of 304 subjects, n=85 demonstrated a shallow trochlea (depth ≤3mm; 28%). In these, and also in a random sample of controls with normal trochlear depth (n=50), the facetal ratio and the sulcus angle were calculated and knee structural abnormalities were assessed by using a modified Whole-Organ-MR-Imaging Score (WORMS). Cartilage segmentation was performed and T(2) relaxation times and patellar cartilage volume were determined. ANOVA and multivariate regression models were used for statistical analysis of the association of MRI structural measures and trochlear morphology. RESULTS: Knees with a shallow trochlea showed higher patellofemoral degeneration (WORMS mean ±standard deviation, 11.2±0.5 versus 5.7±0.6; Multivariate regression, P<0.001) and lower patellar cartilage volume than controls (900±664mm(3) versus 1671±671mm(3); P<0.001). Knees with an abnormal medial-to-lateral facetal ratio (<0.4) showed increased patellofemoral WORMS scores (12.3±0.9 versus 8.3±0.5; P<0.001). Knees with an abnormal sulcus angle (>170°) also showed increased WORMS scores (12.2±1.1 versus 8.6±0.6; P=0.003). T(2) values at the patella were significantly lower in the dysplasia group with a shallow trochlea. However, significance was lost after adjustment for cartilage volume (P=0.673). CONCLUSION: Trochlear dysplasia, defined by a shallow trochlea, was associated with higher WORMS scores and lower cartilage volume, indicating more advanced osteoarthritis at the patellofemoral joint