Antero-medialisation of the tibial tubercle for patellar instability

We reviewed 19 patients (24 knees) with patellofemoral instability treated surgically with antero-medialisation of the tibial tubercle and lateral retinacular release. Twenty-two knees had recurrent patellar dislocation and two patellar subluxation. Lateral retinacular release was performed arthroscopically in 15 knees. Average follow-up was 52 (16–86) months. There was one postoperative haemarthrosis and one failed fixation, which needed surgical revision. The average Lysholm score improved from 63.3 to 98 and only one knee had persistent patello-femoral pain postoperatively. The patellar tilt angle improved from 9.4° to 5.5°. There were no redislocations. We find that the surgical technique produces a consistent correction of patellar instability, but long-term studies are needed to confirm whether it can prevent arthritic degeneration.

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Résumé Nous avons examiné 19 malades (24 genoux) avec une instabilité rotulienne traitée chirurgicalement par antéro-médialisation du tubercule tibial et ouverture de l'aileron externe. Vingt-deux genoux avaient une luxation rotulienne périodique et deux une subluxation rotulienne. La section de l'aileron externe a été faite sous arthroscopie dans 15 genoux. Le suivi moyen était de 52 (16–86) mois. Il y avait une hémarthrose postopératoire et un échec de fixation qui a nécessité une révision chirurgicale. Le score moyen de Lysholm a été amélioré de 63,3 à 98 et un seul genou avait une douleur rotulienne persistante postopératoire. L'angle d'inclinaison rotulien a été amélioré de 9,4° à 5,5°. Il n'y avait pas de nouvelle luxation. Nous pensons que cette technique chirurgicale corrige correctement l'instabilité rotulienne, mais des études à long terme sont nécessaires pour confirmer si elle peut prévenir la dégénérescence arthrosique.

     

Indications in the treatment of patellar instability

Recent developments in patellar instability have focused on the passive restraints against mediolateral patellar motion. Viewed from this perspective, muscle alignment is considered secondary because, although muscle forces are important, their ability to cause or prevent patellar dislocation depends on passive stability or the lack thereof. In the normal knee, the patella seats quickly in the trochlea in early flexion, so that the ligamentous restraints are important only near full extension. In the unstable patellofemoral joint, the trochlea frequently is deficient and patella alta often exists. In such cases, the ligaments assume a greater role in preventing excessive lateral patellar displacement. The most pressing questions at the moment are: 1) which of the anatomical abnormalities must be corrected, alone or in combination, to prevent further patellar instability; and 2) what is the relative risk of corrective procedures compared to the natural history or competing surgical approaches? These questions must be addressed by clinical trials. Only a minority of patients who experience patellar dislocation will redislocate the patella, and surgical treatment does not always yield results that are superior to conservative care. Treatment recommendations should be based on an individual's risk of recurrent dislocation, pain, and disability, a thorough understanding of his or her anatomy, and clear treatment objectives. Lateral release has no role in the treatment of a hyperlax patellofemoral joint, as it adds additional laxity to a system that is already unstable. If surgery is performed, current evidence suggests techniques aimed at repair or reconstruction of the passive retinacular restraints are as effective as more extensive procedures at preventing subsequent dislocations. Among the latter procedures, realignment procedures use active muscle forces to help seat the patella in the femoral groove; however, biomechanical costs are associated with this approach and superior results have not been demonstrated with distal and combined realignments compared with more limited proximal procedures.     

The long-term results of tibial tubercle transfer for patellar instability

The authors report results of a series of 57 tibial tubercle transfers in 46 patients between 1974 and 1984. Of 95 patients operated on for objective and potential patellar instability, 57 (67%) were reviewed with an average follow-up of 14.9 years. At follow-up 19.3% were free of pain. There were no recurrent patellar subluxations and 49.2% of patients were satisfied with the operation as regards episodes of instability. Early medial tibio-femoral arthritis was found in 5 cases. In two there was complete loss of the joint line and in one case complete loss of the medial patellofemoral joint line. Follow-up did not allow us to make an assessment of the adverse role of the tibial tubercle transfer on the patello-femoral and medial tibio-femoral compartment. We consider that the secondary effects are due to a failure to respect the contraindications, which for us were genu varum, previous medial meniscectomy and transfer with a normal tuberosity/trochlea offset rather than due to the transfer itself. The authors believe that tibial tubercle transfer is still indicated in the treatment of objective and potential patellar instability if the symptomatology is dominated by instability and dislocation of the patella and if the tuberosity/trochlea offset is greater than 20 mm.     

膝关节镜下外侧支持带松解及内侧支持带紧缩治疗急性髌骨脱位

目的探讨膝关节镜下外侧支持带松解及内侧支持带紧缩治疗急性髌骨脱位。方法1999年7月～2003年7月共对11例急性髌骨脱位患者施行膝关节镜手术,松解外侧支持带及外侧髌—股韧带,同时紧缩缝合内侧支持带及内侧髌—股韧带。结果平均随访21.2个月,所有病人均未发生再脱位,亦无残留髌骨不稳。膝关节活动度(ROM)正常。结论本术式疗效确切,具有创伤小、并发症少、功能恢复快等优点。     

Three-dimensional transfer of the tibial tuberosity for patellar instability with patella alta

Background

Although patellar instability can be treated with several surgical procedures, the appropriate surgical treatment for patellar instability with patella alta has not yet been investigated. The objective of this study is to find out whether three-dimensional transfer of the tibial tuberosity elicits good knee functionality with improved patella alta and prevents further patellar dislocation.

Methods

Twelve knees (10 patients) underwent surgery for patellar instability with patella alta from 2007 to 2011. The surgery performed was a three-dimensional transfer for the anteromedial distalization of the tibial tuberosity. Predisposing anatomical factors for patellar instability were evaluated preoperatively; femorotibial angle (FTA), patella alta (IS ratio), trochlear dysplasia (sulcus angle) and tilting angle (lateral tilt). The function of the knee was assessed before and after surgery by Lysholm and Kujala score.

Results

Before surgery, the IS ratio was 1.34 ± 0.13, lateral tilt was 22.4° ± 6.5°, and the sulcus angle was 151.7° ± 8.3°, indicating patella alta, laterality, and trochlear dysplasia. After surgery, the IS ratio and lateral tilt significantly improved to 0.95 ± 0.13, and 10.6° ± 3.4°, respectively. FTA and sulcus angle were not altered. Lysholm and Kujala score improved from 63.8 to 94.7 and 67.0 to 94.1 points, respectively. Most patients displayed good outcomes except for one patient who suffered re-dislocation by hitting their knee on the floor, 2.5 years after surgery.

Conclusion

Three-dimensional tibial tuberosity transfer was shown to correct the patella position and result in a good clinical outcome. This method is introduced as an alternative surgery for patellar instability with patella alta.     

Surgical treatment for patellar instability.

The initial therapy for patellofemoral pain remains conservative. Once this treatment plan fails and examination has clearly identified the cause of the patellofemoral dysfunction, surgical treatment is considered. No single procedure corrects all patellofemoral problems, and the patient's age, the causative factor, the condition of the articular surface, and the level of activity should be considered. Surgical options include lateral retinacular release, proximal realignment, distal realignment, and proximal and distal realignment.     

髌骨不稳定的诊治现状

髌骨不稳定是前膝痛的常见原因,是髌股关节常见疾病,是髌骨软骨软化、髌股关节骨性关节炎的重要病因之一.本文通过探讨髌骨不稳定的病理机制、症状、理学检查和影像学,提出准确诊断是合理治疗的前提,治疗的重点是恢复髌骨周围软组织的平衡,选择手术原则上应根据患者不同年龄、不稳定程度、不同的病理因素确定各个手术方案,一般采用联合综合矫正术式.     

Transposition of the posterior tibial tendon

The posterior tibial tendon was rerouted by the technique described by Baker and Hill in 35 feet of children with a dynamic varus deformity due to spastic cerebral palsy. The average follow-up period was 11.4 years. In ten of the feet, rerouting of the posterior tibial tendon was the only procedure performed. Eight of the ten feet obtained a satisfactory correction. There were no overcorrection problems in these ten feet. In the remaining 25 feet, the Baker-Hill procedure was done concurrently with other procedures, such as lengthening of the triceps surae (22 feet), calcaneal osteotomy (two feet), or plantar fascia release (two feet). The dynamic equinovarus deformity was corrected in all 25, but three subsequently developed a cavus deformity. This was probably caused by excessive weakening of the triceps surae rather than transposition of the posterior tibial tendon. Based on this study, anterior rerouting of the posterior tibial tendon seems to be a simple, safe, and generally effective procedure for correction of dynamic varus of the spastic hindfoot in children with cerebral palsy.     

Lateral patellar retinaculum tension in patellar instability

The patellar retinaculum is important in patellar tracking. However, little attention has been paid to the biomechanics of the retinaculum. This study assessed the change in tension of the lateral patellofemoral ligament before and after anteromedial tibial tubercle transfer for patellar instability. Twenty-seven knees in 21 patients were studied and the mean age of the patients at surgery was 19 years. A buckle transducer was clamped on the lateral patellofemoral ligament and the transducer was calibrated to zero with the knee at full extension. The knee then was flexed 30 degrees, 60 degrees, 90 degrees, and 120 degrees, and the transducer recorded changes in tension within the lateral patellofemoral ligament. After anteromedial tibial tubercle transfer, lateral patellofemoral ligament tension was measured in the same manner. Although average lateral patellofemoral ligament tension increased with knee flexion with the maximum at 120 degrees flexion, these changes showed four different patterns measuring variability of patellar instability. An increase of lateral patellofemoral ligament tension after anteromedial tibial tubercle transfer meant that lateral retinacular release should be done concurrently to balance patellar tracking. This information may be useful in deciding the appropriate surgical procedure for each patient.     

Reconstruction of the medial patellofemoral ligament for treatment of patellar instability

Background and purpose Postoperative pain is often severe after total knee arthroplasty (TKA). We investigated the efficacy of the local infiltration analgesia (LIA) technique, both intraoperatively and postoperatively.

Methods 48 patients undergoing TKA were randomized into 2 groups in a double-blind study. In group A, 400 mg ropivacaine, 30 mg ketorolac, and 0.5 mg epinephrine were infiltrated periarticularly during operation. In group P, no injections were given. 21 h postoperatively, 200 mg ropivacaine, 30 mg ketorolac, and 0.1 mg epinephrine were injected intraarticularly in group A, and the same volume of saline was injected in group P. All patients were followed up for 3 months.

Results Median morphine consumption was lower in group A during the first 48 h: 18 (1–74) mg vs. 87 (36–160) mg in group P. Postoperative pain was lower at rest in group A during the first 27 h, and on movement during the first 48 h, except at 21 h. Time to fulfillment of discharge criteria was shorter in group A than in group P: 3 (1–7) vs. 5 (2–8) days. Patient satisfaction was higher in group A than in group P on days 1 and 7. The unbound venous blood concentration of ropivacaine was below systemic toxic blood concentrations.

Interpretation The local infiltration analgesia (LIA) technique provides excellent pain relief and lower morphine consumption following TKA, resulting in shorter time to home readiness and higher patient satisfaction. There were few side effects and systemic LA concentrations were low.