Emily A. Eismann

Complications of Medial Patellofemoral Ligament Reconstruction in Young Patients

Background: The medial patellofemoral ligament (MPFL) has been recognized as the primary restraint to lateral subluxation of the patella. Reconstruction of the MPFL for patellar instability has demonstrated early clinical success, but postoperative complications have rarely been reported, especially in young patients. Purpose: To assess early complications (<3 years) of MPFL reconstruction in young patients. Study Design: Case series; Level of evidence, 4. Methods: The charts and radiographs of all patients who underwent MPFL reconstruction between 2005 and 2011 were retrospectively reviewed to identify postoperative complications. A complication was considered major if the patient required hospitalization or further surgery. Each complication was analyzed to identify the technical factors related to it. Results: A total of 179 knees underwent MPFL reconstruction during the study period. There were 38 complications in 29 knees (16.2%), with 34 major and 4 minor. Major complications included recurrent lateral patellar instability (8 patients), knee motion stiffness with flexion deficits (8 patients), patellar fractures (6 patients), and patellofemoral arthrosis/pain (5 patients). Eighteen of 38 (47%) complications were secondary to technical factors and were considered preventable. Female sex and bilateral MPFL reconstructions were risk factors associated with postoperative complications. Conclusion: Complications occurred in 16.2% of MPFL reconstruction surgeries for patellar instability in young patients, with almost half resulting from technical problems. Patients should be counseled preoperatively on the risk of potential complications.

Juvenile Osteochondritis Dissecans: Is It a Growth Disturbance of the Secondary Physis of the Epiphysis?

OBJECTIVE The primary physis is responsible for longitudinal bone growth. Similarly, epiphysial growth relies on endochondral ossification from the circumferential secondary physeal [corrected]. injury can result in disruption of normal ossification. The cause of juvenile osteochondritis dissecans (OCD) remains elusive. We hypothesized that juvenile OCD results from an insult affecting endochondral ossification from the secondary physis. The purpose of our study was to evaluate the MRI appearance of the distal femoral epiphysis-particularly the secondary physis-of children with juvenile OCD and to compare these findings with the MRI findings of unaffected children. MATERIALS AND METHODS Knee MRI examinations of 30 children (age range, 8 years 8 months to 13 years 4 months) with OCD and 30 matched control patients were evaluated for skeletal maturity; location of the OCD lesion, if present; secondary physeal [corrected] continuity; overlying chondroepiphysial integrity, contour, and width; signal intensity of subchondral bone; and secondary physeal [corrected] conspicuity. Variables were compared using chi-square tests. RESULTS All children were skeletally immature. Condylar lesions were medial in 24 knees and lateral in six knees. All were in the middle one third, posterior one third, or middle and posterior thirds in the sagittal plane. The majority of lesions spanned the intercondylar and middle one third of the femoral condyle in the coronal plane (73%). There was a significant difference between secondary physeal [corrected] disruption in juvenile OCD condyles compared with unaffected condyles (p < 0.001) and control condyles (p < 0.001). Compared with unaffected and control condyles, the OCD group showed chondroepiphysial widening (p < 0.001) and subchondral bone edema (p < 0.001) on MRI. Neither chondroepiphysial integrity nor chondroepiphysial contour was significantly different between groups (p = 0.21, p = 0.31, respectively). CONCLUSION MRI of children with OCD consistently showed secondary physis disruption, overlying chondroepiphysial widening, and subchondral bone edema. We suggest that disruption of normal endochondral ossification may be associated with juvenile OCD.

Mid- to long-term outcomes in adolescent idiopathic scoliosis after instrumented posterior spinal fusion: a meta-analysis.

Study Design. Meta-analysis on mid- to long-term outcomes in adolescent idiopathic scoliosis after instrumented posterior spinal fusion. Objective. To compare mid- to long-term outcomes and complications of the most commonly used instrumentation systems in adolescent idiopathic scoliosis. Summary of Background Data. A meta-analysis of mid- to long-term results of different methods of instrumentation, including the most currently used all-pedicle screw construct, is lacking. Methods. A structured literature review was conducted for studies concerning management of patients with adolescent idiopathic scoliosis with instrumented posterior fusion. Pooled means, standard deviations, and sample sizes were either identified or calculated on the basis of the results of each study. Results. Meta-analyses were performed on outcomes from 27 studies. Overall, 1613 patients who had been treated with Harrington rods, 361 patients who had undergone Cotrel-Dubousset instrumentation, and 298 patients who managed with all-pedicle screw constructs were reviewed. The mean follow-up was 14.9 years. Cotrel-Dubousset and pedicle screw instrumentations achieved a significantly greater degree of correction of the thoracic curve than Harrington rods (40.3° vs. 14.7°; P < 0.001 and 21.9° vs. 14.7°; P = 0.005, respectively). Cotrel-Dubousset technique achieved a significantly higher degree of correction than all-pedicle screw construct in both the thoracic (40.3° vs. 21.9°, respectively; P < 0.001) and lumbar curves (37.2° vs. 16°, respectively; P < 0.001). Similarly, Cotrel-Dubousset construct achieved a greater correction of both thoracic kyphosis (33.5° vs. 23°, respectively; P < 0.001) and lumbar lordosis (46° vs. 50.7°, respectively; P = 0.002) than pedicle screws. All-pedicle screw fixation was associated with the lower risk of pseudarthrosis, infection, neurological deficit, and reoperation. Conclusion. This study confirms the negative effect of Harrington rods on sagittal alignment. We further found that the degree of correction in the coronal and sagittal planes was higher after Cotrel-Dubousset instrumentation than all-pedicle screw fixation. All-pedicle screw constructs offered the lower risk of mid- to long-term complications and revision surgery.

All-pedicle screw versus hybrid instrumentation in adolescent idiopathic scoliosis surgery: a comparative radiographical study with a minimum 2-Year follow-up.

Study Design. Comparative analysis of 2 groups of patients who underwent surgical treatment of adolescent idiopathic scoliosis (AIS). Objective. To compare a segmental pedicle screw only system with a hybrid system for the treatment of Lenke type 1 AIS curves. Summary of Background Data. Although previous AIS studies have tried to compare various constructs with the all-pedicle screw fixation, all have failed to address important confounding variables, such as skeletal maturity, preoperative flexibility of the curve, and factors associated with a multicenter or multisurgeon analysis. Methods. The medical records and spinal radiographs of patients with AIS treated surgically by a single surgeon between 2000 and 2009 were retrospectively reviewed. Patients with Lenke type 1 curves and minimum follow-up of 2 years were divided into 2 groups that were meticulously matched: group 1 consisted of patients in whom the all-pedicle screw construct was used, whereas group 2 included patients who were treated with the hybrid hook-screw system. Results. Group 1 included 34 patients and group 2 included 29 patients. At the last follow-up, thoracic curve correction averaged 70.4% for the all-pedicle screw group and 60% for the hybrid group (P = 0.19). The all-pedicle screw group showed a significantly greater increase in thoracic kyphosis than the hybrid group system (P = 0.04). Global sagittal balance showed greater improvement in the all-pedicle screw group during the immediate postoperative that was lost by the last follow-up. The all-pedicle screw system revealed less intraoperative blood loss but greater operating time than the hybrid construct. After controlling for length of follow-up, no statistical difference in any of the radiographical parameters measured was recorded. Conclusion. With the exception of global sagittal balance, the pedicle screw system provided better maintenance of its corrective parameters when followed for greater than two years. Level of Evidence: 3

The effects of denervation, reinnervation, and muscle imbalance on functional muscle length and elbow flexion contracture following neonatal brachial plexus injury.

The pathophysiology of paradoxical elbow flexion contractures following neonatal brachial plexus injury (NBPI) is incompletely understood. The current study tests the hypothesis that this contracture occurs by denervation‐induced impairment of elbow flexor muscle growth. Unilateral forelimb paralysis was created in mice in four neonatal (5‐day‐old) BPI groups (C5‐6 excision, C5‐6 neurotomy, C5‐6 neurotomy/repair, and C5‐T1 global excision), one non‐neonatal BPI group (28‐day‐old C5‐6 excision), and two neonatal muscle imbalance groups (triceps tenotomy ± C5‐6 excision). Four weeks post‐operatively, motor function, elbow range of motion, and biceps/brachialis functional lengths were assessed. Musculocutaneous nerve (MCN) denervation and reinnervation were assessed immunohistochemically. Elbow flexion motor recovery and elbow flexion contractures varied inversely among the neonatal BPI groups. Contracture severity correlated with biceps/brachialis shortening and MCN denervation (relative axon loss), with no contractures occurring in mice with MCN reinnervation (presence of growth cones). No contractures or biceps/brachialis shortening occurred following non‐neonatal BPI, regardless of denervation or reinnervation. Neonatal triceps tenotomy did not cause contractures or biceps/brachialis shortening, nor did it worsen those following neonatal C5‐6 excision. Denervation‐induced functional shortening of elbow flexor muscles leads to variable elbow flexion contractures depending on the degree, permanence, and timing of denervation, independent of muscle imbalance.

Novel Radiographic Feature Classification of Knee Osteochondritis Dissecans A Multicenter Reliability Study

Background: Osteochondritis dissecans (OCD) is a vexing condition for patients, parents, and physicians because of the frequent slow healing and nonhealing that leads to prolonged treatment. Several features on plain radiographs have been identified as predictors of healing, but the reliability of their measurement has not been established. Purpose: To determine the inter- and intrarater reliability of several radiographic features used in the diagnosis, treatment, and prognosis of OCD femoral condyle lesions. Study Design: Cohort study (Diagnosis); Level of evidence, 3. Methods: Pretreatment anteroposterior, lateral, and notch radiographs of 45 knees containing OCD lesions of the medial or lateral femoral condyle were reviewed in blinded fashion by 7 orthopaedic physician raters from different institutions over a secure web portal at 2 time points over a month apart. Classification variables included lesion location, growth plate maturity, parent bone radiodensity, progeny bone fragmentation, progeny bone displacement, progeny bone contour, lesion boundary, and radiodensity of the lesion center and rim. Condylar width and lesion size were measured on all views. Interrater reliability was assessed using free-marginal kappa and intraclass correlations. Intrarater reliability was assessed using the Cohen kappa, linear-weighted kappa, and intraclass correlations based on measurement type. Results: Raters had excellent reliability for differentiating medial and lateral lesions and growth plate maturity and for measuring condylar width and lesion size. In the subset of knees with visible bone in the lesion, the fragmentation, displacement, boundary, central radiodensity, and contour (concave/nonconcave) of the lesion bone were classified with moderate to substantial reliability. The radiodensity of the lesion rim and surrounding epiphyseal bone were classified with poor to fair reliability. Conclusion: Many diagnostic features of femoral condyle OCD lesions can be reliably classified on plain radiographs, supporting their future testing in multifactorial classification systems and multicenter research to develop prognostic algorithms. Other radiographic features should be excluded, however, because of poor reliability.

Glenohumeral Abduction Contracture in Children with Unresolved Neonatal Brachial Plexus Palsy

BACKGROUND Following neonatal brachial plexus palsy, the Putti sign-obligatory tilt of the scapula with brachiothoracic adduction-suggests the presence of glenohumeral abduction contracture. In the present study, we utilized magnetic resonance imaging (MRI) to quantify this glenohumeral abduction contracture and evaluate its relationship to shoulder joint deformity, muscle atrophy, and function. METHODS We retrospectively reviewed MRIs of the thorax and shoulders obtained before and after shoulder rebalancing surgery (internal rotation contracture release and external rotation tendon transfer) for twenty-eight children with unresolved neonatal brachial plexus palsy. Two raters measured the coronal positions of the scapula, thoracic spine, and humeral shaft bilaterally on coronal images, correcting trigonometrically for scapular protraction on axial images. Supraspinatus, deltoid, and latissimus dorsi muscle atrophy was assessed, blinded to other measures. Correlations between glenohumeral abduction contracture and glenoid version, humeral head subluxation, passive external rotation, and Mallet shoulder function before and after surgery were performed. RESULTS MRI measurements were highly reliable between raters. Glenohumeral abduction contractures were present in twenty-five of twenty-eight patients, averaging 33° (range, 10° to 65°). Among those patients, abductor atrophy was present in twenty-three of twenty-five, with adductor atrophy in twelve of twenty-five. Preoperatively, greater abduction contracture severity correlated with greater Mallet global abduction and hand-to-neck function. Abduction contracture severity did not correlate preoperatively with axial measurements of glenohumeral dysplasia, but greater glenoid retroversion was associated with worse abduction contractures postoperatively. Surgery improved passive external rotation, active abduction, and hand-to-neck function, but did not change the abduction contracture. CONCLUSIONS A majority of patients with persistent shoulder weakness following neonatal brachial plexus palsy have glenohumeral abduction deformities, with contractures as severe as 65°. The abduction contracture occurs with abductor atrophy, with or without associated adductor atrophy. This contracture may improve global shoulder abduction by positioning the glenohumeral joint in abduction. Glenohumeral and scapulothoracic kinematics and muscle pathology must be further elucidated to advance an understanding of the etiology and the prevention and treatment of the complex shoulder deformity following neonatal brachial plexus palsy. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The reliability to determine "healing" in osteochondritis dissecans from radiographic assessment.

Background: Current literature supporting treatment strategies for osteochondritis dissecans (OCD) has limited prognostic utility. Presently, there is no gold standard for an OCD “healing” outcome. Accurate and reliable determination of the OCD healed status on the basis of radiographs would be valuable to provide a guide for evidence-based treatment of OCD. The purpose of this study was to determine interrater and intrarater reliability of radiographic assessment of OCD lesion healing in the knee. Methods: A hospital database identified 39 consecutive patients with OCD in 42 knees, who were treated conservatively for at least 6 months. Patients were an average age of 11.9 years (±2.4 y). A total of 102 presentation slides were prepared, each containing 2 similar radiographic views from the same patient taken 6 months (±1 mo) apart. These slides were then categorized by 4 reviewers (1 orthopaedic surgeon, 1 orthopaedic fellow, and 2 musculoskeletal radiologists) blinded to patient data, as healed, not healed, or unable to evaluate the OCD lesion. Reviewers repeated their assessment at a minimum of 3 weeks after their first read. Intrarater and interrater reliability were measured with the Cohen &kgr; coefficient and Randolph’s free-marginal multirater &kgr;, respectively, and with the percent agreement. Results: OCD lesion categorization demonstrated insufficient interrater reliability with a &kgr; of 0.44 and 63% agreement. The notch view had the highest interrater reliability with a &kgr; of 0.63% and 76% agreement, and the lateral view had the lowest interrater reliability with a &kgr; of 0.29% and 53% agreement. The OCD lesion categorization demonstrated substantial intrarater reliability with a &kgr; of 0.68% and 81% agreement. Conclusions: Reviewers did not consistently agree on the “healing” status of the OCD lesions on the basis of radiographic assessments. Standard criteria to assess healing are needed to consistently evaluate OCD knee lesions in children. Level of Evidence: Not applicable.

Prevention of arthrofibrosis after arthroscopic screw fixation of tibial spine fracture in children and adolescents.

Arthrofibrosis is a major complication of tibial spine fracture treatment in children, potentially resulting in knee pain, quadriceps weakness, altered gait, decreased function, inability to return to sports, and long-term osteoarthritis. Thus, prevention rather than treatment of arthrofibrosis is desirable. The purpose of this study was to evaluate an aggressive postoperative rehabilitation and early intervention approach to prevent permanent arthrofibrosis after tibial spine fracture treatment and to compare epiphyseal and transphyseal screws for fixation. A consecutive series of 24 patients younger than age 18 with displaced type II and III tibial spine fractures who underwent arthroscopic reduction and screw fixation between 2006 and 2011 were retrospectively reviewed. Final range of motion was compared between patients with epiphyseal (n=12) and transphyseal (n=9) screws. One-third (4 of 12) of patients with epiphyseal screws underwent arthroscopic debridement and screw removal approximately 3 months postoperatively; 3 patients lacked 5° to 15° of extension, 1 experienced pain with extension, and 1 had radiographic evidence of screw pullout, loss of reduction, and resultant malunion. In the transphyseal screw group, 3 patients had 10° loss of extension, and all corrected after arthroscopic debridement and screw removal. The two groups did not significantly differ in time to hardware removal or return to sports or final range of motion. No growth disturbances were identified in patients after transphyseal screw removal. An aggressive approach of postoperative rehabilitation and early intervention after arthroscopic reduction and screw fixation of tibial spine fractures in children was successful in preventing permanent arthrofibrosis.

Does medial patellofemoral ligament reconstruction decrease patellar height? A preliminary report.

Background: The purpose of this study was to evaluate the hypothesis that medial patellofemoral ligament (MPFL) reconstruction for patellar instability decreases patellar height. Methods: Preoperative and postoperative lateral knee radiographs of 38 adolescents who underwent MPFL reconstruction between 2005 and 2011 were reviewed. The Insall-Salvati index, Blackburne-Peel index, Caton-Deschamps index, and plateau-patella angle were measured on all radiographs to identify differences in patellar height. These patellar height indices were also measured on lateral knee radiographs of 25 adolescents (control group) who were treated conservatively for osteochondritis dissecans of the knee. The 2 groups were compared to account for patellar height changes secondary to growth and ossification. Intrarater reliability was measured for all patellar height indices at 1-month interval. Results: Preoperatively, patients who underwent MPFL reconstruction had significantly greater patellar height on all indices compared with the control group before and after controlling for age and sex. The patients who underwent MPFL reconstruction showed a significantly greater decrease in patellar height on the Blackburne-Peel or Caton-Deschamps indices over time compared with the control group such that postoperatively there was no difference between groups in these patellar height indices. Furthermore, the change in patellar height indices after MPFL reconstruction did not differ between patients with less than or more than 1-year follow-up. All indices demonstrated good to excellent intrarater reliability. Conclusions: The present study showed a decrease in patellar height in the postoperative period in patients after MPFL reconstruction for patellar instability. Further investigation is necessary to determine the long-term effects of MPFL reconstruction on patellar height. Level of Evidence: Level III—therapeutic, case series.