Pigmented villonodular synovitis/giant cell tumor in the knee.

PURPOSE OF REVIEW: Pigmented villonodular synovitis (PVNS) is a rare diagnosis in pediatric patients and commonly presents with symptoms of swelling and pain. Early diagnosis is important to prevent secondary degeneration into the subchondral bone. This review will analyze the etiology, clinical signs/symptoms, diagnosis, treatment, and recent literature on PVNS in the pediatric population. RECENT FINDINGS: Many theories of PVNS etiology have been described in the literature; however, an inflammatory response has been most widely accepted. PVNS can occur in any joint, but most commonly in the knee. The most common treatment for PVNS is synovectomy, and long-term follow-up is necessary to detect disease persistence or recurrence. SUMMARY: Although uncommon, PVNS does occur in the pediatric population and this diagnosis should be included in the differential of atraumatic joint swelling and pain.

No Association Between Growth Hormone Therapy and Upper Extremity Physeal Tension Injuries: A Matched Case-control Study.

BACKGROUND: Recent evidence has identified a strong association between growth hormone therapy and physeal injuries in the lower extremity; however, few studies have investigated this association in the upper extremity. QUESTIONS/PURPOSES: (1) Do pediatric patients with physeal tension injuries of the shoulder and elbow have higher odds of having exposure to recombinant growth hormone therapy than matched controls? (2) Are the odds of having exposure to recombinant growth hormone therapy in physeal tension injuries different when stratified by shoulder and elbow injuries? METHODS: Using a matched case-control study design, patients between 4 and 18 years of age treated at a large, urban, academic center from February 1, 2016, to November 6, 2023, were identified by ICD-10 codes using EPIC SlicerDicer, an electronic medical record-based data mining tool. Patients diagnosed with physeal tension injuries in the shoulder or elbow were included in the case group, and those with midshaft radius, metaphyseal radius, or both-bone forearm fractures were included in the control group. A total of 618 patients with physeal injuries and 1244 with non-physeal fractures were identified and screened for inclusion. After further chart review to confirm diagnoses, 46% (283) of patients with physeal injuries and 54% (670) of patients with non-physeal fractures were included. A further 6% (16) of patients with physeal injuries and 2% (15) of patients with non-physeal injuries were excluded due concomitant dislocations or missing data, resulting in 267 eligible patients with physeal injuries and 655 eligible patients with non-physeal fractures. Two patients with concurrent elbow and shoulder physeal injuries were additionally excluded from stratified analyses. Patients with physeal injuries and non-physeal fractures were 1:1 matched by age ± 0.5 years, sex, and BMI ± 2 kg/m2. In all, 522 patients were included in the analysis, including 261 patients with physeal injuries and 261 with non-physeal fractures. The mean ± SD ages for both patient groups was 13 ± 2 years (p = 0.44), 88% (229 of 261) of all participants were male, and the mean BMIs were 19.9 ± 3.0 kg/m2 and 19.4 ± 3.0 kg/m2 (p = 0.11), respectively. Growth hormone exposure was compared between patients with physeal injuries and non-physeal fractures using a conditional logistic regression model. RESULTS: Overall, 4% (10 of 261) of patients with physeal injuries had exposure to growth hormone therapy as compared with 2% (4 of 261) of patients with non-physeal fractures (OR 2.5 [95% confidence interval 0.8 to 8.0]). Subgroup analyses of shoulder and elbow injuries demonstrated no difference in growth hormone exposure between patients with physeal injuries and non-physeal fractures (OR 2 [95% CI 0.4 to 10.2] and OR 3 [95% CI 0.6 to 14.9], respectively). CONCLUSION: In light of these results, clinicians may not need to advise precaution against sports or other activities that put the upper extremity physes under stress when treating patients with growth hormone supplementation therapy. Future multicenter studies, however, are indicated to further investigate for the existence of any subtle association between growth hormone therapy and upper extremity physeal injuries relative to the large association previously noted in the lower extremity in pediatric and adolescent patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

Simultaneous MPFL reconstruction and guided growth result in low rates of recurrent patellofemoral instability.

PURPOSE: Implant-mediated guided growth (IMGG) is used to address coronal plane deformity in skeletally immature patients. Few studies have reported on IMGG and simultaneous medial patellofemoral ligament (MPFL) reconstruction for paediatric patients with concurrent genu valgum and patellofemoral instability (PFI). This study aimed to report on the outcomes of these simultaneous procedures. MATERIALS AND METHODS: This was a retrospective review of paediatric patients undergoing simultaneous MPFL reconstruction and IMGG between 2016 and 2023. Mechanical lateral distal femoral angle (mLDFA), hip-knee-ankle angle (HKA) and mechanical axis deviation (MAD) were measured on full-length hip-to-ankle plain radiographs. Measurements were taken preoperatively, prior to implant removal and/or at final follow-up with minimum 1-year clinical follow-up. RESULTS: A total of 25 extremities in 22 patients (10 female) underwent simultaneous IMGG and MPFL reconstruction. The mean age at surgery was 12.6 ± 1.7 years. The mean duration of implant retention was 18.6 ± 11.3 months. Nineteen extremities (76%) underwent implant removal by final follow-up. Preoperative HKA corrected from a mean of 5.8 ± 2.3° to -0.8 ± 4.5° at implant removal or final follow-up (p < 0.001), with mLDFA and MAD similarly improving (both p < 0.001). HKA corrected a mean of 0.7 ± 0.9° per month, while mLDFA and MAD corrected a mean of 0.5 ± 0.6°/month and 2 ± 3 mm/month, respectively. At the time of implant removal or final follow-up, 88% of patients demonstrated alignment within 5° of neutral. Only one extremity experienced subsequent PFI (4%). For 14 patients who underwent implant removal with further imaging at a mean of 7.8 ± 4.9 months, only one patient (7%) had a valgus rebound to an HKA > 5°. CONCLUSION: Simultaneous MPFL reconstruction and IMGG provided successful correction of lower extremity malalignment with only one recurrence of PFI. This approach is a reliable surgical option for skeletally immature patients with genu valgum and PFI. LEVEL OF EVIDENCE: Level 4 case series.

Hemiepiphysiodesis for Genu Valgum in Patients With Multiple Hereditary Exostoses.

BACKGROUND: Genu valgum is a well-known feature of multiple hereditary exostoses (MHE). Though prior reports have demonstrated successful treatment with hemiepiphysiodesis, details regarding the correction rate and comparison to an idiopathic population are lacking. This study aimed to detail our institution's experience with guided growth of the knee in patients with MHE and compare this to an idiopathic population. METHODS: All pediatric patients (age 18 and younger) with MHE who underwent lower extremity hemiepiphysiodesis at a tertiary care medical center between January 2016 and December 2022 were retrospectively reviewed. Preoperative and postoperative mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA, the primary outcomes) were measured in addition to mechanical axis deviation (MAD) and hip-knee-ankle angle (HKA). Patients were 1:2 matched based on age, sex, and physes instrumented to a cohort with idiopathic genu valgum. RESULTS: A total of 21 extremities in 16 patients with MHE underwent hemiepiphysiodesis of the distal femur, proximal tibia, and/or distal tibia. The mean age at surgery was 11.7±2.2 years. Mean MAD corrected from zone 1.9±0.7 to -0.3±1.5, while mLDFA corrected from 83.4±2.9 to 91.7±5.2 degrees and MPTA corrected from 95.3±3.6 to 90.5±4.0 degrees in distal femurs and proximal tibias undergoing guided growth, respectively. Three extremities (14.3%) experienced overcorrection ≥5 degrees managed with observation. There were no differences in correction rates per month for mLDFA (0.54±0.34 vs. 0.51±0.29 degrees, P =0.738) or MPTA (0.31±0.26 vs. 0.50±0.59 degrees, P =0.453) between MHE and idiopathic groups. For 11 extremities in the MHE group with open physes at hardware removal, they experienced a mean recurrence of HKA of 4.0±3.4 degrees at 19-month follow-up. CONCLUSION: Hemiepiphysiodesis corrects lower extremity malalignment in patients with MHE at a similar rate compared with an idiopathic coronal plane deformity population. Rebound deformity of 4 degrees at 19 months after hardware removal in patients with remaining open growth plates should make surgeons conscious of the remaining growth potential when planning deformity correction. LEVEL OF EVIDENCE: Level III.

Stepwise lengthening of quadriceps extensor mechanism for severe obligatory and fixed patella dislocators: Four-year clinical and surgical outcomes.

OBJECTIVES: The purpose of this study was to report clinical and surgical outcomes of medial patellofemoral ligament reconstruction (MPFLR) and concomitant quadriceps lengthening to treat fixed and obligatory patellofemoral instability (PFI) in the pediatric population. METHODS: Patients with obligatory or fixed PFI who underwent simultaneous MPFLR and quadriceps lengthening from 2008 to 2020 were reviewed. Of the 413 records, 24 fit the inclusion criteria. Demographic information, surgical details, associated diagnoses, and outcome measures were collected for each knee. Complications and additional surgeries were also obtained. RESULTS: The final cohort included 20 patients (10 male, 10 female), with a total of 24 knees. The average age at the time of surgery was 11.9 â€‹± â€‹3.1 (5.4-17.3). Seventeen were obligatory dislocators in flexion and 7 were fixed dislocators. Average follow-up was 4.3 â€‹± â€‹2.4 (1.3-9.4) years. One patient was lost to follow-up and excluded from the study. The mean outcome measures were as followed; KOOS 82, HSS Pedi-FABS 9, IKDC 76, Kujala 78, BPII 67, and SANE 90. Six patients had subsequent instability episodes. Ten patients had a subsequent surgery. CONCLUSIONS: Reports on quadriceps lengthening to treat PFI in the pediatric population are rare. Six (25 â€‹%) of the 24 knees included had subsequent PFI. Although this is a high rate of recurrent instability, no second surgeries were indicated for infection, extensor mechanism weakness, or contracture. The authors conclude that simultaneous MPFLR and stepwise quadriceps lengthening can be used to effectively manage fixed and obligatory PFI in this difficult patient population. LEVEL OF EVIDENCE: IV.

Temporary hemi-epiphysiodesis with tension band plates in skeletally immature patients with genu valgum: Faster correction in patients with more than 2 years of expected time of growth remaining.

Purpose: Hemi-epiphysiodesis procedures in skeletally immature patients are commonly done to correct genu valgum over time. This study seeks to demonstrate the average rate of deformity correction for genu valgum using hinged tension band plates, while examining different age groups and sex-related differences. Methods: A retrospective chart review of patients who underwent hemi-epiphysiodesis with hinged tension band plates for valgus knee deformity from 2012 to 2022 by one pediatric orthopaedic surgeon was performed. Expected time of growth remaining was calculated as the difference between age of skeletal maturity and bone age at time of surgery. The mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, mechanical femoral tibia angle, screw divergence angle, and hinge angle were measured immediately after implant placement and prior to implant removal. Results: 54 skeletally immature patients were treated for pathologic genu valgum. The mean age at time of surgery was 12.5 ± 1.9 years. The radiographic measurement of the valgus deformity between the beginning and end of treatment showed significant correction (p = 0.002). The lower limb axis of the younger cohort corrected significantly faster (7.5 ± 4.6°/year) than the older cohort (5.3 ± 2.8°/year) (p = 0.030). The mechanical lateral distal femoral angle correction rate was also significantly different between the two cohorts (7.0 ± 4.7°/year vs. 4.8 ± 2.8°/year, respectively (p = 0.002)). The group with greater expected time of growth remaining demonstrated a significantly faster rate of correction than the group with less than 2 years of growth remaining (p < 0.001). Conclusion: This study reaffirms the finding that timing is essential when performing temporary hemi-epiphysiodesis for valgus knee deformity in skeletally immature patients.

The Number of Patellar Dislocation Events Is Associated With Increased Chondral Damage of the Trochlea.

BACKGROUND: Patellofemoral instability is associated with chondral injuries to the patella, trochlea, and lateral femoral condyle. Although studies have demonstrated an association between patellar dislocations and chondral injuries, the influence of the number of dislocations on chondrosis is not established. PURPOSE: To elucidate the precise association between the number of patellar dislocation events and the severity of chondral injuries in a multicenter cohort study at the time of patellar stabilization procedures. STUDY DESIGN: Cross-sectional study; Level of evidence, 2. METHODS: A prospective multicenter cohort study (JUPITER [Justifying Patellar Instability Treatment by Early Results]) database was queried for cases of primary patellofemoral instability procedures from December 2016 to September 2022. Cartilage lesions were classified using the International Cartilage Repair Society (ICRS) classification system during an arthroscopic or open evaluation (direct visualization), with grades 2 to 4 considered abnormal. The number of dislocations was categorized as 1, 2-5, and >5. Categorical variables were compared with the chi-square test, and binary logistic regression was performed to identify predictors of the presence of chondral lesions. RESULTS: A total of 938 knees (mean age, 16.2 ± 3.8 years; 61.4% female) were included, with 580 (61.8%) demonstrating a chondral injury. The most affected region was the patella (n = 498 [53.1%]), followed by the lateral femoral condyle (n = 117 [12.5%]) and trochlea (n = 109 [11.6%]). There were no differences in the presence (P = .17) or grade (P = .63) of patellar lesions by the number of dislocations. Patients with >5 dislocations more frequently had trochlear chondral lesions (19.8%) compared with those with fewer dislocations (1, 7.6%; 2-5, 11.0%; P < .001). More dislocations were also associated with a higher proportion of ICRS grade 2 to 4 trochlear lesions (>5, 15.3%; 2-5, 10.0%; 1, 6.9%; P = .015). Combined patellar and trochlear lesions were also more common in those with >5 dislocations (P = .001). In multivariable regression, >5 dislocations was the only variable predictive of a trochlear lesion (odds ratio, 3.03 [95% CI, 1.65-5.58]; P < .001). CONCLUSION: This large prospective cohort study demonstrated that recurrent patellar dislocations can lead to more severe chondral damage in specific locations in the knee. More than 5 dislocations was associated with a >3-fold increase in the incidence and severity of trochlear chondral injuries. There were no differences in the presence or grade of patellar lesions by the number of dislocations. These findings should caution surgeons regarding prolonged nonoperative treatment.

Quadriceps Tendon Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients: 3-Year Clinical and Patient-Reported Outcomes.

BACKGROUND: The rate of anterior cruciate ligament (ACL) rupture in active, skeletally immature patients is increasing. Although hamstring tendon autograft (HTA) was previously deemed the gold standard, recent studies have shown HTA to have a high failure rate in this high-risk population of young competitive athletes, and quadriceps tendon autograft (QTA) has yielded excellent preliminary outcomes in some studies examining this population. PURPOSE: To evaluate 3-year clinical and patient-reported functional outcomes of primary ACL reconstruction (ACLR) with soft tissue QTA in skeletally immature patients. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Skeletally immature patients who underwent ACLR with a full-thickness soft tissue QTA were included. Preoperative patient and surgical data were collected. The ACLR technique was selected predicated upon skeletal age and included all-epiphyseal and complete transphyseal techniques. Patients were followed for a minimum of 2 years with successive clinical visits or were contacted via telephone. Patients who did not have minimum 2-year follow-up after 3 contact attempts via telephone were excluded. Information regarding return to sports (RTS) and concomitant or subsequent surgical procedures was collected. Pediatric International Knee Documentation Committee (Pedi-IKDC), Hospital for Special Surgery Functional Activity Brief Scale (HSS Pedi-FABS), and Single Assessment Numeric Evaluation (SANE) scores were collected. RESULTS: Of 85 adolescent patients aged 11.1 to 17.6 years (mean age, 14.1 ± 1.2 years), 2 patients were determined to be lost to follow-up after 3 failed contact attempts. Of the patients included in this study (N = 83), 26 patients (31%) underwent all-epiphyseal and 57 patients (69%) underwent complete transphyseal ACLR. Additionally, 48 patients (58%) underwent concomitant lateral extra-articular tenodesis using the iliotibial band with a modified Lemaire technique. The mean follow-up time was 3.7 ± 1.2 years (range, 2-7 years). Twenty (24%) patients had subsequent surgical procedures, of which 3 (4%) were due to graft failures. At a mean 3-year follow-up, the mean Pedi-IKDC, HSS Pedi-FABS, and SANE scores were 90, 23, and 94 respectively; the RTS rate was 100%; and the rate of RTS at the previous level of performance was 93%. CONCLUSION: Use of a soft tissue QTA for ALCR in a high-risk skeletally immature population of athletes resulted in excellent postoperative outcomes with low rates of graft failure and high return to sport rates.