Slocum Center for Orthopedics and Sports Medicine

Distal radius fractures are the most common fracture of childhood, occurring in ∼1 per 100 children annually. Given the high incidence of these fractures, we explored feasibility of a bundled payment model. We determined the total treatment costs for each child and identified components of fracture management that contributed to variations in cost. We retrospectively reviewed all hospital and physician costs related to the treatment of closed distal radius fractures at a large academic children's hospital. We included all children age 2 to 15 years treated by an orthopaedic surgeon for an isolated closed distal radius fracture between 2013 and 2015. We compared total treatment costs by fracture management approach. We then estimated the contribution of each component of fracture management to total treatment costs using linear regression. We identified 5640 children meeting the inclusion criteria, of which 4602 (81.6%) received closed treatment without manipulation, 922 (16.3%) underwent closed reduction in the clinic, emergency department, or radiology procedure suite, and 116 (2.1%) underwent treatment in the operating room. The median cost for closed treatment without manipulation was $1390 [interquartile range (IQR) 1029 to 1801], compared with $4263 (IQR, 3740 to 4832) for closed reduction and $9389 (IQR, 8272 to 11,119) for closed reduction and percutaneous pinning (P<0.001). In multivariable regression analysis, fracture management approach and use of the operating room environment were the largest cost drivers (P<0.001, R=0.88). Closed reduction in the clinic or emergency department added $894 (95% confidence interval, 819-969) to treatment costs, while closed reduction in the operating room added $5568 (95% confidence interval, 5224-6297). Location of the initial clinical evaluation, number of radiographic imaging series obtained, and number of orthopaedic clinic visits also contributed to total costs. Closed pediatric distal radius fractures treated without manipulation show small variations in treatment costs, making them well suited for bundled payment. Bundled payments for these fractures could reduce costs by encouraging adoption of existing evidence-based practices. Level III-therapeutic.

Analysis of 2- and 7-year outcomes from a clinical trial comparing 2-level cervical disk arthroplasty (CDA) to anterior cervical discectomy and fusion (ACDF) in 287 patients with radiculopathy alone, and 110 patients with myelopathy alone or myelopathy with radiculopathy. To compare the long-term safety and effectiveness of CDA for myelopathy versus radiculopathy. CDA for myelopathy is safe and effective in short term. We analyzed Neck Disability Index (NDI), neck/arm pain, SF-36, neurological status, adverse events (AEs), and secondary surgeries at index and adjacent levels. All groups improved significantly for NDI, neck/arm pain, and physical component summary (PCS) scores from preoperative to postoperative. CDA Myelopathy versus CDA Radiculopathy: 2- and 7-year improvements were not significantly different. The 7-year score improvements for CDA Myelopathy and CDA Radiculopathy were: NDI (37.8 vs. 35.8, P=0.352), neck pain (12.0 vs. 12.1, P=0.477), arm pain (11.6 vs. 9.6, P=0.480), and PCS (14.1 vs. 13.7, P=0.863). The 2 groups had similar proportions of patients who maintained or improved their neurological status (87.2% vs. 93.5%, P=0.218), similar rates of serious AEs (54.5% vs. 57.5%, P=0.291) and similar rates of secondary surgeries at index (3.7% vs. 4.4%, P=0.839) and adjacent levels (3.7% vs. 7.6%, P=0.367). CDA Myelopathy versus ACDF myelopathy: 2 and 7-year improvements were not significantly different. The 7-year CDA and ACDF score improvements were: NDI (37.8 vs. 31.1, P=0.147), neck pain (12.0 vs. 10.4, P=0.337), arm pain (11.6 vs. 11.4, P=0.791), and PCS (14.1 vs. 11.2, P=0.363). The 2 groups had statistically similar proportions who maintained or improved their neurological status (87.2% vs. 96.2%, P=0.409), statistically similar overall rates of secondary surgeries at the index levels (3.7% vs. 9.4%, P=0.374), and statistically similar rates of secondary surgeries at adjacent levels (3.7% vs. 15.4%, P=0.088). CDA group demonstrated lower rates of serious AEs than ACDF (54.5% vs. 65.9%, P=0.019). CDA for myelopathy is a safe and effective long-term treatment.

Background:Substantial muscle atrophy occurs after total knee arthroplasty (TKA), resulting in decreased strength and impaired mobility. We sought to determine whether perioperative supplementation with essential amino acids (EAA) would attenuate muscle atrophy following TKA and whether the supplements were safe for ingestion in an older surgical population.Methods:We performed a double-blind, placebo-controlled, randomized trial of 39 adults (age range, 53 to 76 years) undergoing primary unilateral TKA who ingested 20 g of EAA (n = 19) or placebo (n = 20) twice daily for 7 days preoperatively and for 6 weeks postoperatively. At baseline and 6 weeks postoperatively, magnetic resonance imaging (MRI) scans were obtained to measure quadriceps and hamstrings muscle volume. Secondary outcomes included functional mobility and strength. Data on physical activity, diet, and patient-reported outcomes (Veterans RAND 12-Item Health Survey and Knee injury and Osteoarthritis Outcome Score) were collected. Safety was determined through blood tests evaluating blood urea nitrogen, creatinine, creatinine clearance, homocysteine, and renal and liver function. Laboratory values at baseline, on the day of surgery, and at 2 days, 2 weeks, and 6 weeks postoperatively were compared between treatment groups. Analysis of covariance models, with baseline values as covariates, were used to evaluate outcomes between treatment groups. P values were adjusted for multiple tests.Results:Compared with baseline, the EAA group had significantly less decrease in mean quadriceps muscle volume compared with the placebo group in the involved leg (−8.5% ± 2.5% compared with −13.4% ± 1.9%; p = 0.033) and the contralateral leg (−1.5% ± 1.6% compared with −7.2% ± 1.4%; p = 0.014). The hamstrings also demonstrated a greater muscle-volume-sparing effect for the EAA group than for the placebo group in the involved leg (−7.4% ± 2.0% compared with −12.2% ± 1.4%; p = 0.036) and contralateral leg (−2.1% ± 1.3% compared with −7.5% ± 1.5%; p = 0.005). There were no differences between the groups in terms of functional measures or strength. Blood chemistry values varied significantly between assessments periods but did not statistically differ between groups.Conclusions:The results of the present study suggest that EAA supplementation is safe and reduces the loss of muscle volume in older adults recovering from TKA.Level of Evidence:Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Axial dynamization of fractures can promote healing, and overly stiff fixation can suppress healing. A novel technology, termed active plating, provides controlled axial dynamization by the elastic suspension of locking holes within the plate. This prospective, controlled animal study evaluated the effect of active plates on fracture-healing in an established ovine osteotomy model. We hypothesized that symmetric axial dynamization with active plates stimulates circumferential callus and delivers faster and stronger healing relative to standard locking plates. Twelve sheep were randomly assigned to receive a standard locking plate or an active locking plate for stabilization of a 3-mm tibial osteotomy gap. The only difference between plates was that locking holes of active plates were elastically suspended, allowing up to 1.5 mm of axial motion at the fracture. Fracture-healing was analyzed weekly on radiographs. After sacrifice at nine weeks postoperatively, callus volume and distribution were assessed by computed tomography. Finally, to determine their strength, healed tibiae and contralateral tibiae were tested in torsion until failure. At each follow-up, the active locking plate group had more callus (p < 0.001) than the standard locking plate group. At postoperative week 6, all active locking plate group specimens had bridging callus at the three visible cortices. In standard locking plate group specimens, only 50% of these cortices had bridged. Computed tomography demonstrated that all active locking plate group specimens and one of the six standard locking plate group specimens had developed circumferential callus. Torsion tests after plate removal demonstrated that active locking plate group specimens recovered 81% of their native strength and were 399% stronger than standard locking plate group specimens (p < 0.001), which had recovered only 17% of their native strength. All active locking plate group specimens failed by spiral fracture outside the callus zone, but standard locking plate group specimens fractured through the osteotomy gap. Symmetric axial dynamization with active locking plates stimulates circumferential callus and yields faster and stronger healing than standard locking plates. The stimulatory effect of controlled motion on fracture-healing by active locking plates has the potential to reduce healing complications and to shorten the time to return to function.

Total knee arthroplasty (TKA) utilizes a tourniquet to reduce blood loss, maintain a clear surgical "bloodless" field, and to ensure proper bone-implant cementing. In 2007, over 600,000 TKAs were performed in the United States, and this number is projected to increase to 3.48 million procedures performed annually by 2030. The acute effects of tourniquet-induced ischemia-reperfusion (I/R) on human skeletal muscle cells are poorly understood and require critical investigation, as muscle atrophy following this surgery is rapid and represents the most significant clinical barrier to long-term normalization of physical function. To determine the acute effects of I/R on skeletal muscle cells, biopsies were obtained at baseline, maximal ischemia (prior to tourniquet release), and reperfusion (following tourniquet release). Quadriceps volume was determined before and 2 wk post-TKA by MRI. We measured a 36% decrease in phosphorylation of Akt Ser(473) during ischemia and 37% during reperfusion (P < 0.05). 4E-BP1 Thr(37/46) phosphorylation decreased 29% during ischemia and 22% during reperfusion (P < 0.05). eEF2 Thr(56) phosphorylation increased 25% during ischemia and 43% during reperfusion (P < 0.05). Quadriceps volume decreased 12% in the TKA leg (P < 0.05) and tended to decrease (6%) in the contralateral leg (P = 0.1). These data suggest cap-dependent translation initiation, and elongation may be inhibited during and after TKA surgery. We propose that cap-dependent translational events occurring during surgery may precipitate postoperative changes in muscle cells that contribute to the etiology of muscle atrophy following TKA.

Several mechanical studies suggest locking plate constructs may inhibit callus necessary for healing of distal femur fractures. However, the rate of nonunion and factors associated with nonunion are not well established. We (1) determined the healing rate of distal femur fractures treated with locking plates, (2) assessed the effect of patient injury and treatment variables on fracture healing, and (3) compared callus formation in fractures that healed with those that did not heal. We retrospectively reviewed 82 patients treated with 86 distal femur fractures using lateral locking plates. We reviewed all charts and radiographs to determine patient and treatment variables and then determined the effects of these variables on healing. We quantitatively measured callus at 6, 12, and 24 weeks. The minimum time for telephone interviews and SF-36v2(TM) scores was 1 year (mean, 4.2 years; range, 1-7.2 years). Fourteen fractures (20%) failed to unite. Demographics and comorbidities were similar in patients who achieved healing compared with those who had nonunions. There were more empty holes in the plate adjacent to fractures that healed; comminuted fractures failed to heal more frequently than less comminuted fractures. Less callus formed in fractures with nonunions and in patients treated with stainless steel plates compared with titanium plates. Complications occurred in 28 of 70 fractures (40%), 19 of which had additional surgery. We found a high rate of nonunion in distal femur fractures treated with locking plates. Nonunion presented late without hardware failure and with limited callus formation suggesting callus inhibition rather than hardware failure is the primary problem. Mechanical factors may play a role in the high rate of nonunion.

Retrieval studies of total hip replacements with highly cross-linked ultra-high-molecular-weight polyethylene liners have shown much less surface damage than with conventional ultra-high-molecular-weight polyethylene liners. A recent revision hip replacement for recurrent dislocation undertaken after only five months revealed a highly cross-linked polyethylene liner with a large area of visible delamination. In order to determine the cause of this unusual surface damage, we analysed the bearing surfaces of the cobalt-chromium femoral head and the acetabular liner with scanning electron microscopy, energy dispersive x-ray spectroscopy and optical profilometry. We concluded that the cobalt-chromium modular femoral head had scraped against the titanium acetabular shell during the course of the dislocations and had not only roughened the surface of the femoral head but also transferred deposits of titanium onto it. The largest deposits were 1.6 microm to 4.3 microm proud of the surrounding surface and could lead to increased stresses in the acetabular liner and therefore cause accelerated wear and damage. This case illustrates that dislocations can leave titanium deposits on cobalt-chromium femoral heads and that highly cross-linked ultra-high-molecular-weight polyethylene remains susceptible to surface damage.

Locked plating constructs may be too stiff to reliably promote secondary bone healing. This study used a novel imaging technique to quantify periosteal callus formation of distal femur fractures stabilized with locking plates. It investigated the effects of cortex-to-plate distance, bridging span, and implant material on periosteal callus formation. Retrospective cohort study. One Level I and one Level II trauma center. Sixty-four consecutive patients with distal femur fractures (AO types 32A, 33A-C) stabilized with periarticular locking plates. Osteosynthesis using indirect reduction and bridge plating with periarticular locking plates. Periosteal callus size on lateral and anteroposterior radiographs. Callus size varied from 0 to 650 mm2. Deficient callus (20 mm2 or less) formed in 52%, 47%, and 37% of fractures at 6, 12, and 24 weeks postsurgery, respectively. Callus formation was asymmetric, whereby the medial cortex had on average 64% more callus (P=0.001) than the anterior or posterior cortices. A longer bridge span correlated minimally with an increased callus size at Week 6 (P=0.02), but no correlation was found at Weeks 12 and 24 postsurgery. Compared with stainless steel plates, titanium plates had 76%, 71%, and 56% more callus at Week 6 (P=0.04), Week 12 (P=0.03), and Week 24 (P=0.09), respectively. Stabilization of distal femur fractures with periarticular locking plates can cause inconsistent and asymmetric formation of periosteal callus. A larger bridge span only minimally improves callus formation. The more flexible titanium plates enhanced callus formation compared with stainless steel plates.