Carlo Camathias

Treating Patella Instability in Skeletally Immature Patients

PURPOSE The purpose of this study was to comprehensively and systematically review the current evidence for orthopaedic treatment of immature and adolescent patients with acute and chronic patellar instability. METHODS We searched the online databases PubMed, CINAHL, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews for relevant publications on patellar instability. All dates and languages were included. RESULTS Twenty articles reporting on a total of 456 knees in 425 patients (131 male patients, 294 female patients) followed-up for 56.7 ± 42.2 months on average were included in the analysis. Two studies focused specifically on conservative versus surgical treatment in acute dislocations and reported no difference in outcomes after 7 and 14 years, even in the face of slight trochlear dysplasia. For recurrent instability, we found consistent beneficial effects from surgical stabilization on clinical scores, postoperative stability, and radiographic assessment. There is no evidence for growth disturbance with surgical patellar stabilization in immature patients. CONCLUSIONS The current best evidence does not support the superiority of surgical intervention over conservative treatment in an acute patellar dislocation. However, anatomic variations and their effect on healing should be considered and included in decision making. In recurrent patellar instability in pediatric and adolescent patients with normal or restored knee anatomy, reconstruction of the medial patellofemoral ligament (MPFL) is the most effective treatment option and can be done safely, together with extensor realignment as needed. LEVEL OF EVIDENCE Level IV, systematic review of mixed-level studies.

Routine pin tract care in external fixation is unnecessary: a randomised, prospective, blinded controlled study.

INTRODUCTION Pin site infections are seen in up to 40% of external fixators (ExFix) and are therefore the most common complication with this device. There is no consensus in the literature as to the appropriate regimen for pin tract care and infection prevention. This study is the first intra-subject, randomised, prospective controlled trial comparing daily pin tract care to no pin tract care at all. METHOD Consecutive patients series (56 patients, 16 female, age 4-68 y, mean 24 y, in total 204 pins) recruited in the National Referral Hospital in Honiara in the Solomon Islands over a 2 year period. Exclusion criteria were application of ExFix for less than two weeks or a non-standard ExFix. Pin treatment was allocated into groups anatomically, proximal and distal. Randomisation was intra-subject and intra-group: 101 pins had daily pin site care and 103 had no treatment at all. ENDPOINTS Soft-tissue interface, stability of the pins, torsional stability as determined with a torque metre, osteolysis and pain. Assessment of pin sites blinded. Statistical analysis using the paired t test for parametric data and the Wilcoxon rank test for non-parametric data (Stat View). RESULTS No significant difference between the two groups. Soft-tissue interface 36% vs. 35% (granulation/secretion), stability 20 vs 25 pins with loosening. No significant osteolysis (7 vs. 6 pins). Torque: mean 0.75 Nm, max.: 3.05 Nm vs. 0.60 Nm, max.: 3.55 Nm, no significant difference. No differences in demographics (age, localisation, sex, time of fixation). CONCLUSION This study shows that routine pin tract care is unnecessary in external fixation treatment of injuries.

Long-term results and outcome predictors in one-stage hip reconstruction in children with cerebral palsy.

BACKGROUND One-stage hip reconstruction is the gold standard for treatment of hip displacement in children with cerebral palsy. The aims of this study were (1) to report the subjective clinical, objective clinical, and radiographic outcomes; and (2) to investigate outcome predictors, including the influence of the following risk factors: femoral head shape, migration percentage, direction of migration, and age at surgery. METHODS We reviewed 168 hip reconstructions (eighty-two right, eighty-six left) in 121 patients (101 male, twenty female) at a mean follow-up of 7.3 ± 4.6 years (range, four to eighteen years). Surgical outcomes were assessed on the basis of the pain intensity and frequency (measured on 10-point visual analog scales) as well as GMFCS (Gross Motor Function Classification System) and MCPHCS (Melbourne Cerebral Palsy Hip Classification System) scores and postoperative migration percentage. The effects of femoral head shape, preoperative migration percentage, direction of migration, and age at surgery on surgical outcome were assessed by multivariate regression adjusting for potential confounders including sex, triradiate cartilage status, type of cerebral palsy, and surgical technique. RESULTS Pain intensity and frequency were reduced significantly. Preoperative femoral head shape had no significant effect on the changes in pain, MCPHCS grade, and GMFCS level. The preoperative migration percentage was the most influential risk factor with respect to postoperative outcome. Age at surgery had no effect on the changes in pain score and GMFCS level. The overall surgical complication rate was 10.5%. CONCLUSIONS Our data on 168 hip reconstructions at a mean follow-up of seven years showed significant and clinically meaningful improvements in pain intensity and frequency as well as in clinical scores and hip coverage. Analysis of potential risk factors showed only the preoperative migration percentage to have a relevant influence on outcomes.

Patellar tendon shortening for flexed knee gait in spastic diplegia.

UNLABELLED We evaluated the outcome of three different approaches to the management of flexed knee gait patients with spastic diplegia. The three surgical procedures were patellar tendon shortening (PTS), PTS combined with rotational osteotomies of the femur and/or tibia, and PTS combined with supracondylar extension osteotomy (SEO) of the distal femur. The primary outcome measure was gait kinematics. The knee gait variable score (GVS) and the gait profile score (GPS) were derived from gait kinematics. 24 patients (16 male and 8 female), mean age 16.1 years (SD 5.8 years), who had surgery between 2002 and 2008, were followed for a mean of 22 months. Knee extension during gait improved by a mean of 20° throughout the gait cycle, with an improvement in the knee GVS of 14° (p<0.001). The overall gait pattern improved with a mean decrease in GPS of 4.6°. Correction of patella alta was demonstrated by an improvement in the Koshino index from 1.34 pre-operatively to 1.10 post-operatively (p<0.001). Knee and gait kinematics, physical examination measures and Koshino Index improved in all three surgical groups, suggesting that a tailored approach to the correction of flexed knee gait in spastic diplegia is both feasible and appropriate. LEVEL OF EVIDENCE Level III.

Distal femoral osteotomy using the LCP pediatric condylar 90-degree plate in patients with neuromuscular disorders.

Background: In patients with cerebral palsy and other neuromuscular disorders, correction of a fixed knee flexion deformity is thought to be crucial for the improvement of gait. The distal femoral extension osteotomy (DFO) is one method to achieve this goal. The standard implant for fixation of the 2 fragments in DFO is the conventional AO blade plate. The aim of this study was to report the outcome of using the new LCP Pediatric Condylar 90-Degree Plate for DFO. Methods: Thirty-eight patients undergoing 63 DFOs were included. The mean age was 16.3±4.4 years (range, 4 to 27 y) at the time of surgery. Thirty-two patients had a diagnosis of cerebral palsy and 6 patients had other neuromuscular disorders including myelomeningocoele and arthrogryposis. Thirteen patients had unilateral procedures and 25 had bilateral procedures. Results: The mean duration of the surgical intervention was 67.9±26.5 minutes (range, 30 to 180 min) and the mean blood loss was 100.0±42.1 mL (range, 50 to 250 mL). In 84% of the cases, large-fragment (5.0 mm) implants were used. The mean extension correction in 84% of the patients (n=53) was 22.8±10.3 degrees (range, 5 to 50 degrees). In this series, there were 2 complications in 63 osteotomies (3%). Radiologic follow-up of the cohort was until the time of plate removal (14.2±4.3 mo; range, 6 to 26 mo). Three months after the index operation, all osteotomies were radiologically consolidated. At this time and at plate removal, there were no malunions or nonunions in this cohort. Clinical follow-up of the cohort was performed until the end of the study (mean 35.5±6.7 mo; range, 22 to 46 mo). At the end of the study, 59 plates (94%) had been removed. Conclusions: The new LCP Pediatric Condylar 90-Degree Plate provides stable and safe fixation of distal femoral correction osteotomies in patients with neuromuscular disorders. Level of Evidence: Level IV.

Bioabsorbable lag screw fixation of knee osteochondritis dissecans in the skeletally immature

Osteochondritis dissecans (OCD) of the knee in children is associated with more morbidity than previously recognized. Sixteen knees in 13 children with symptomatic OCD lesions in the knee diagnosed with MRI underwent arthroscopic fixation using polylactide biodegradable lag screws, after failing a minimum of 6 months conservative treatment. The mean age was 12.3 years; 14 lesions were in the medial condyle, two in the lateral condyle, and the mean area was 244 mm2. Early physiotherapy was prescribed with no period of immobilization and the patients were followed for a mean of 27 months. One patient, who required a concomitant meniscal repair, developed a transient neurapraxia of the peroneal nerve but went on to full recovery. All patients but this one had returned to sport at 4-month follow-up. There was significant improvement in the knee function scores and all patients reported their knees as improved or much improved. We propose that simple arthroscopic fixation of OCD with SmartScrews is an effective treatment in the pediatric population leading to a rapid recovery of premorbid function.

Trochleoplasty as a Solitary Treatment for Recurrent Patellar Dislocation Results in Good Clinical Outcome in Adolescents

Background: The essential static patellar stabilizer is a normal-shaped trochlear groove. A dysplastic groove destabilizes the patella. Trochleoplasty approaches this underlying condition and reshapes the trochlea. However, studies have reported on trochleoplasty for revision cases or as accompanied by other interventions. The effect of trochleoplasty alone remains unexplained. Purpose: To introduce trochleoplasty as a stand-alone treatment for recurrent patellar dislocation and to compare its pre- to postoperative functional and clinical variables. Study Design: Case series; Level of evidence, 4. Methods: A trochleoplasty was performed in 50 knees (27 right) in 44 patients (30 females; mean ± SD age, 15.6 ± 2.0 years). The indication for surgery was recurrent patellar dislocation not responding to nonoperative treatment (>6 months), with types B through D dysplasia and closed or closing physes in adolescents aged 10 to 20 years. Assessment included J-sign and apprehension test, Kujala and Lysholm scores, patients’ subjective assessment and activity level according to the International Knee Documentation Committee questionnaire, and patients’ overall satisfaction. The Caton-Deschamps ratio and the lateral condyle index were measured. Pre- versus postoperative values were compared with a paired Wilcoxon signed-rank test. The minimum follow-up was 24 months (33 ± 10.6 months). Results: The Kujala score improved from 71 preoperatively to 92 postoperatively (P < .001) and the Lysholm score from 71 to 95 (P < .001). Patients’ subjective assessment improved at the final follow-up as compared with that preoperatively (P < .001). Most patients enhanced their activity (P < .001), and their overall satisfaction increased postoperatively (P < .001). Preoperatively, there was a positive J-sign in 45 knees and a positive apprehension test in 41 knees. Both markers disappeared postoperatively in 39 and 33 knees, respectively, leaving 6 knees with a positive J-sign and 8 knees with a positive apprehension test (P < .001). One patella redislocated postoperatively after 38 months. Four patients required a single arthroscopic debridement. Conclusion: In this study, trochleoplasty as a solitary treatment for recurrent patellofemoral dislocations in patients with trochlear dysplasia resulted in good clinical outcomes if severe torsional and axial malalignment was excluded. Kujala and Lysholm scores increased postoperatively, as well as subjective International Knee Documentation Committee assessment of outcomes, activity level, and overall satisfaction.

Implant Failure After Biodegradable Screw Fixation in Osteochondritis Dissecans of the Knee in Skeletally Immature Patients

PURPOSE The primary purpose of this study was to retrospectively assess the incidence of bioabsorbable screw failure in skeletally immature patients treated for osteochondritis dissecans (OCD) of the knee. The second purpose was to assess implant degradation, focusing on differential breakdown of the intraosseous and extraosseous parts of the screw on magnetic resonance imaging (MRI). METHODS In this retrospective study, 24 patients (30 knees) with MRI-confirmed OCD were treated with a total of 61 biodegradable screws and followed up for a minimum of 2 years or until the onset of new symptoms. MRI scans were performed every 6 months to assess differences in signal intensity between the head and body of the screw. The angle between the surface of the head and the body of the screw was measured, with an angle greater than 90° interpreted as indicating a broken screw (i.e., failed implant). RESULTS Seven screws (all 2.7 mm, 11.5% of all screws) in 5 patients were considered broken screws. The implant failed completely in an additional 4 patients with breakage of 7 of 9 screws; 3 patients were considered late failures, occurring after more than 6 months. Altogether, 14 of a total of 61 screws (23%) were broken. CONCLUSIONS Screw breakage is a surprisingly frequent cause of failure in resorbable OCD fixation in skeletally immature patients. MRI data showed differential decomposition of the screw within and outside of bone as a possible cause. LEVEL OF EVIDENCE Level IV, therapeutic case series.

First 50 Pediatric and Adolescent Elbow Arthroscopies: Analysis of Indications and Complications.

Background: Elbow arthroscopy is a challenging, yet extremely productive procedure in orthopaedic sports medicine. The severely confined anatomy of the pediatric and adolescent elbow is particularly prone for perioperative complications. This study focuses on the indications and complications of the first 50 elbow arthroscopies in skeletally immature patients done in a specialized pediatric orthopaedic department. Purpose: To review analysis of indications and complications in pediatric and adolescent elbow arthroscopy. We hypothesized that the complication rate in these patients is similar to adults. Methods: Data on 50 consecutive elbow arthroscopies were prospectively gathered in a dedicated database and retrospectively analyzed for indications and perioperative complications. All procedures were performed by a surgeon trained in orthopaedic sports medicine. Results: A total of 26 boys and 24 girls with a mean age of 13.6±3.3 years at the time of surgery and a minimum follow-up of 1 year were included. Fifty-eight percent were treated for osteochondritis dissecans, 24% for arthrofibrosis, 14% for a congenital disorder, and 4% for a posttraumatic problem other than arthrofibrosis. The complication rate was 8%, including 3 cases of transient neuropraxia and 1 superficial wound infection. There were no major complications such as septic arthritis, vascular injury, or permanent nerve damage. All complications resolved fully with conservative treatment, no revision were required. Discussion: Although osteochondritis dissecans is still the leading reason for such surgery, fractures and posttraumatic conditions are becoming more important. With a rate of 5% to 8% of minor, fully resolving complications such an increase is not a reason for concerns. Level of Evidence: Level IV—case series.

Temporary hemiepiphysiodesis of the distal medial femur: MPFL in danger.

IntroductionTemporary hemiepiphysiodesis (TH) with plate fixation is a well-accepted and common treatment for correcting leg malalignment in skeletally immature patients. The purpose of this study was to investigate any soft tissue damage caused during TH at the distal medial femur with a plate and two screws. We hypothesized that correct plate placement can affect the integrity of the medial stabilizing structures of the knee, especially the medial patellofemoral ligament (MPFL), the medial collateral ligament (MCL) or result in arthrotomy of the knee joint itself.Materials and methodsIn eight cadaveric knees of five adult humans a TH was performed with a plate and two cancellous screws at the distal medial femur using a standardized surgical technique. Subsequently the medial capsular and ligamentous structures were systematically exposed and assessed. Capsular and synovial tissue was also inspected for impingement by the plate or screws.ResultsIn all knees the MPFL was present. In two specimens the MPFL was intact and the plate was lying over the dorsal part of the MPFL close to the MCL. The MPFL was completely cut in two cases in the central part of the ligament. In four cases the MPFL was partially dissected or perforated by a screw and fixed to the femur by the plate. The MCL was intact and not impinged by the implant in any case. In total four of eight knees the capsule was transected or perforated by a screw or by a part of the plate, resulting in intraarticular implant placement.ConclusionsStandard plate placement during TH on the distal medial femur frequently leads to damage to the MPFL, impingement of the MPFL, the capsular and synovial tissues or exposure of the knee joint.