Vivek Chadayammuri

Reconstruction of Long Bone Infections Using the Induced Membrane Technique: Tips and Tricks

UNLABELLED The management of posttraumatic long bone osteomyelitis remains a challenging clinical problem. A systematic approach is necessary, beginning with eradication of the infected bone and soft tissue. There are a number of options for reconstruction of the remaining bone defect, including the induced membrane technique developed by Masquelet. We describe our technique for the 2-stage treatment of long bone osteomyelitis. The first stage involves a radical debridement, stabilization of the bone with either external fixation or an antibiotic-coated intramedullary nail, and placement of a polymethylmethacrylate spacer. The second stage includes excision of the spacer and placement of autologous bone graft. Various resection methods, fixation strategies, antibiotic additives, and types of bone grafts or substitutes can be used. The purpose of our technical article is to share our personal experience and describe several nuances that are critical for the success of this treatment strategy. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Innovative strategies for the management of long bone infection: a review of the Masquelet technique

Post-traumatic long bone osteomyelitis (PTOM) is a relatively frequent occurrence in patients with severe open fractures and requires treatment to prevent limb-threatening complications. The Masquelet technique represents a length-independent, two-staged reconstruction that involves the induction of a periosteal membrane and use of an antibiotic-impregnated cement spacer for the treatment of segmental bone loss that result from bone infection. In this review, we summarize recent developments regarding the diagnosis and treatment of long bone PTOM, with a special emphasis on the use of the Masquelet technique for reconstruction of wide diaphyseal defects.

Lateral Acetabular Coverage Predicts the Size of the Hip Labrum

Background: Bony morphological abnormalities of the hip joint are often accompanied by adaptive soft tissue changes. These adaptive changes, if better understood and characterized, may serve to inform clinical decision making. Purpose: To investigate the correlation between the size of the hip labrum and lateral acetabular coverage in patients at our hip preservation clinic. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A cohort of 236 patients seen at a dedicated hip preservation service between June 2013 and June 2015 were retrospectively analyzed. Patients were grouped according to the degree of acetabular coverage, as measured by the lateral center-edge angle (LCEA): normal acetabular coverage (25°-39.9°), acetabular overcoverage (≥40°), borderline dysplasia (20°-24.9°), and frank dysplasia (<20°). Preoperative magnetic resonance imaging was utilized to measure the length of the labrum at 3 locations: laterally, anteriorly, and anteroinferiorly. Results: Frankly dysplastic and borderline dysplastic hips exhibited larger values of labral length at all locations when compared with hips with normal acetabular coverage (P < .001) or acetabular overcoverage (P < .001). Interestingly, mean labral length values in frank dysplasia were statistically similar to corresponding measurements in borderline dysplasia. In hips with frank dysplasia, borderline dysplasia, or normal acetabular coverage, labral length was consistently greatest at the lateral labrum and correspondingly lowest at the anteroinferior labrum (P < .001). In hips with acetabular overcoverage, labral length did not vary significantly between the lateral, anterior, and anteroinferior locations. Multivariate analyses confirmed LCEA to be the strongest predictor of labral length, irrespective of measurement location. Conclusion: Patients with borderline dysplasia and frank dysplasia exhibited increased values of labral length in the weightbearing zone, potentially indicating a compensatory reaction to the lack of bony coverage. Labral length may serve as an instability marker and inform clinical decision making for patients with borderline dysplasia.

Measurement of lateral acetabular coverage: a comparison between CT and plain radiography

We prospectively evaluated the degree of absolute agreement between measurements of lateral center-edge angle (LCEA) on plain radiography (XR) and computed tomography (CT) in a consecutive cohort of 205 patients (410 hips) undergoing hip arthroscopy. Preoperative measurements of the LCEA were performed bilaterally utilizing standardized anteroposterior radiographs and coronal reformatted CT scans. Demographic variables including age, gender, height, weight, BMI and clinical diagnosis were recorded for all patients. Overall, measured values of the LCEA were 2.1° larger on CT compared with XR (32.9° versus 30.8°, P < 0.001). Subgroup analysis revealed the highest mean difference in hips with acetabular dysplasia and concomitant cam-type femoroacetabular impingement (FAI) [mean difference (CT–XR) 5.5°, 95% confidence interval (CI) 3.7°–7.3°, P = 0.011], followed by hips with isolated acetabular dysplasia (mean difference [CT–XR] 4.9°, 95% CI 2.7°–7.0°, P < 0.001). In contrast, 119 (29.0%) of the hips demonstrated larger measurements of the LCEA on 25 XR relative to CT. Of these hips, 20 (16.8%) had pincer-FAI and 25 had cam-FAI (21.0%), representing a significantly higher proportion compared with all other clinical subgroups (P = 0.045 and 0.036, respectively). Our study demonstrates measured values of the LCEA are consistently inflated on CT relative to XR for a wide variety of hip pathologies, highlighting the need for standardization and validation of CT-based measurements to improve the quality of clinical decision making. Level of Evidence: Diagnostic Level II.

Delayed Anterior Cruciate Ligament Reconstruction in Young Patients With Previous Anterior Tibial Spine Fractures

Background: Avulsion fractures of the anterior tibial spine in young athletes are injuries similar to anterior cruciate ligament (ACL) injuries in adults. Sparse data exist on the association between anterior tibial spine fractures (ATSFs) and later ligamentous laxity or injuries leading to ACL reconstruction. Purpose: To better delineate the incidence of delayed instability or ACL ruptures requiring delayed ACL reconstruction in young patients with prior fractures of the tibial eminence. Study Design: Case series; Level of evidence, 4. Methods: We identified 101 patients between January 1993 and January 2012 who sustained an ATSF and who met inclusion criteria for this study. All patients had been followed for at least 2 years after the initial injury and were included for analysis after completion of a questionnaire via direct contact, mail, and/or telephone. If patients underwent further surgical intervention and/or underwent later ACL reconstruction, clinical records and operative reports pertaining to these secondary interventions were obtained and reviewed. Differences between categorical variables were assessed using the Fisher exact test. The association between time to revision ACL surgery and fracture type was assessed by Kaplan-Meier plots. The association between need for revision ACL surgery and age, sex, and mechanism of surgery was assessed using logistic regression. Results: Nineteen percent of all patients evaluated underwent delayed ACL reconstruction after a previous tibial spine fracture on the ipsilateral side. While there were a higher proportion of ACL reconstructions in type II fractures, there was not a statistically significant difference in the number of patients within each fracture group who went on to undergo later surgery (P = .29). Further, there was not a significant association between fracture type, sex, or mechanism of injury as it related to the progression to later ACL reconstruction. However, there was a significant association between age at the time of injury and progression to later ACL reconstruction (P = .02). For every year increase in age at the time of injury, the odds of going on to undergo delayed ACL reconstruction were greater by a factor of 1.3 (95% CI, 1.1-1.6). Conclusion: Although an ATSF is a relatively rare injury, our cohort of patients suggests that a subset of young patients with all types of tibial spine fractures will require later ACL reconstruction. There is a need to counsel patients that a delayed ACL rupture is a potential risk after an ATSF, especially as children approach skeletal maturity. Further patient follow-up and prospective studies are required.

Passive Hip Range of Motion Predicts Femoral Torsion and Acetabular Version

BACKGROUND Orientation abnormalities of the acetabulum and femur have been implicated in early-onset coxarthrosis. The purpose of this study was to identify clinical examination findings predictive of such hip morphologies. METHODS A consecutive cohort of 221 patients (442 hips) undergoing hip arthroscopy was included. Demographic characteristics including age, diagnosis, sex, height, weight, body mass index (BMI), and physical activity level were recorded. Passive range of motion was measured for all hips. Preoperative computed tomography scans were utilized to measure femoral torsion and central acetabular version, and a combined femoral torsion-acetabular version (COTAV) index was defined as their sum. RESULTS The study cohort comprised 221 patients (sixty-four males, 157 females) with a mean age of 32.5 years and mean BMI of 24.2 kg/m(2). Overall, hips with femoral antetorsion and acetabular anteversion exhibited the greatest internal rotation range of motion at a neutral hip position (mean, 44.2°), whereas hips with femoral retrotorsion and acetabular retroversion demonstrated the lowest corresponding value (20.1°; p < 0.001). Femoral torsion was significantly associated with female sex (p < 0.001), BMI (p < 0.001), and presence of pathology corresponding to cam-type femoroacetabular impingement (FAI) (p = 0.044). Central acetabular version was significantly associated with age (p = 0.021), female sex (p < 0.001), and absence of mixed-type FAI pathology (p = 0.025). Increasing age and internal rotation range of motion at a neutral hip position were the most significant predictors of an increased COTAV index. CONCLUSIONS This study confirmed that passive hip range of motion significantly predicts combined femoral torsion and central acetabular version. Accurate clinical assessment of the COTAV index may inform surgical decision-making in hip preservation surgery.

All-Arthroscopic Ligamentum Teres Reconstruction With Graft Fixation at the Femoral Head-Neck Junction

Ligamentum teres (LT) tears are increasingly being recognized as a source of pain and dysfunction in the hip. Although debridement for partial tears of the LT has long been established as the standard of care with good pain relief, reconstruction has been successfully performed in select patients to address concerns of persistent symptomatic instability. The current technique for femoral tunnel preparation carries the added morbidity of open dissection in the peritrochanteric space, an unnecessarily long tunnel with excessive bone removal, and a need for a very long graft due to distal fixation at the lateral femoral cortex. To address these shortcomings, we present a technique for arthroscopic femoral tunnel drilling at the level of the head-neck junction, allowing for an all-arthroscopic LT reconstruction.

Percutaneous Ultrasound-Guided Hydrodissection of a Symptomatic Sural Neuroma.

Symptomatic neuromas of the sural nerve are a rare but significant cause of pain and debilitation in athletes. Presentation is usually in the form of chronic pain and dysesthesias or paresthesias of the lateral foot and ankle. Treatment traditionally ranges from conservative measures, such as removing all external compressive forces, to administration of nonsteroidal anti-inflammatory drugs, vitamin B6, tricyclic antidepressants, antiepileptics, or topical anesthetics. This article reports a case of sural nerve entrapment in a 34-year-old male triathlete with a history of recurrent training-induced right-sided gastrocnemius strains. The patient presented with numbness in the right lateral foot and ankle that had persisted for 3 months, after he was treated unsuccessfully with extensive nonoperative measures, including anti-inflammatory drugs, activity modification, and a dedicated physical therapy program of stretching and strengthening. Orthopedic assessment showed worsening pain with forced passive dorsiflexion and manual pressure applied over the distal aspect of the gastrocnemius. Plain radiographs showed normal findings, but in-office ultrasound imaging showed evidence of sural nerve entrapment with edema and neuromatous scar formation in the absence of gastrocnemius or soleus pathology. Percutaneous ultrasound-guided hydrodissection of the sural nerve at the area of symptomatic neuroma and neural edema was performed the same day. The patient had complete relief of symptoms and full return to the preinjury level of participation in competitive sports. This case report shows that hydrodissection, when performed by an experienced physician, can be an effective, minimally invasive technique for neurolysis in the setting of sural nerve entrapment, resulting in improvement in clinical symptoms.

Lateral acetabular coverage as a predictor of femoroacetabular cartilage thickness

To investigate the correlation between femoroacetabular cartilage thickness and lateral acetabular coverage in patients undergoing hip arthroscopy for a variety of indications. Articular cartilage at the hip is hypothesized to undergo adaptive change secondary to unique patterns of pathomechanical loading which results in a direct relationship between acetabular coverage and femoroacetabular cartilage thickness. A cohort of 252 patients presenting to our dedicated hip preservation service between June 2013 and June 2015 were retrospectively analysed. Preoperative radiographs and MRI studies were obtained for all symptomatic hips and classified according to radiographic lateral center edge angle (LCEA) as follows: normal acetabular coverage (25–40°), acetabular overcoverage (≥40°), borderline dysplasia (20–24.9°) and frank dysplasia (<20°). Femoroacetabular cartilage thickness was measured on a preoperative MRI-scan at the fovea, middle sourcil, and lateral sourcil. In all groups, cartilage thickness was maximized at the lateral sourcil relative to the middle sourcil or fovea (P < 0.001). Furthermore, articular cartilage thickness was significantly increased when comparing one group to successive groups with diminished lateral acetabular coverage. Indeed, multivariate analyses confirmed LCEA to be the strongest determinant of femoroacetabular cartilage thickness compared with age, gender, body-mass index or presence of cam/pincer lesions. Patients with borderline and frank dysplasia exhibit increased values of femoroacetabular cartilage thickness in the weight-bearing zone, potentially indicating a compensatory reaction to the lack of bony coverage. Articular cartilage thickness may serve as an instability marker and inform clinical decision-making for patients with borderline dysplasia.

Does the OTA Open Fracture Classification Predict the Need for Limb Amputation? A Retrospective Observational Cohort Study on 512 Patients.

Background: Few studies have examined the utility of the Orthopaedic Trauma Association Open Fracture Classification (OTA-OFC) compared to the traditional Gustilo-Anderson classification for prediction of treatment outcomes in patients with open fractures. Questions/Objectives: (1) How do the Gustilo-Anderson classification and OTA-OFC systems compare in accuracy of predicting limb amputation, infection, and need for soft tissue coverage? (2) Is there an OTA-OFC summative threshold score that may guide the discussion and decision-making with regard to limb salvage or amputation? Design: Retrospective observational cohort study; Level IV evidence. Setting: Level I trauma center and urban safety-net institution. Patients/Participants: Consecutive adult patients with open long bone fractures who underwent operative treatment between January 1, 2007 and December 31, 2012. Main Outcome and Measurements: Postoperative complications of infection, early limb amputation, and requirement for soft-tissue procedures. Results: The study cohort comprised 512 patients with mean age 49.6 ± 14.9 years. Nineteen patients (3.7%) underwent amputation. The Gustilo-Anderson classification demonstrated no correlations with any of the primary outcome measures, while OTA-OFC summative scores significantly varied between all outcome comparison groups. The skin injury component of the OTA-OFC was an independent predictor of limb amputation (OR, 5.44; 95% CI, 2.37–12.47), and an OTA-OFC summative score of ≥10 best correlated with need for amputation (P < 0.001). Sensitivity and specificity of the reported model were 79% and 94%, respectively. Conclusions: Our results should be interpreted with caution due to the retrospective nature of our study. Based on our data, the OTA-OFC is superior to the Gustilo-Anderson classification system for prediction of postoperative complications and treatment outcomes in patients with open long bone fractures. A summative threshold score of 10 seems to identify increased odds of successful limb salvage.