Cara A. Cipriano

Heterotopic ossification following traumatic brain injury and spinal cord injury.

&NA; Heterotopic ossification associated with neurologic injury, or neurogenic heterotopic ossification, tends to form at major synovial joints surrounded by spastic muscles. It is commonly associated with traumatic brain or spinal cord injury and with other causes of upper motor neuron lesions. Heterotopic ossification can result in a variety of complications, including nerve impingement, joint ankylosis, complex regional pain syndrome, osteoporosis, and softtissue infection. The associated decline in range of motion may greatly limit activities of daily living, such as positioning and transferring and maintenance of hygiene, thereby adversely affecting quality of life. Management of heterotopic ossification is aimed at limiting its progression and maximizing function of the affected joint. Nonsurgical treatment is appropriate for early heterotopic ossification; however, surgical excision should be considered in cases of joint ankylosis or significantly decreased range of motion before complications arise. Patient selection, timing of excision, and postoperative prophylaxis are important components of proper management.

Serum and Synovial Fluid Analysis for Diagnosing Chronic Periprosthetic Infection in Patients with Inflammatory Arthritis

BACKGROUND The serum erythrocyte sedimentation rate and C-reactive protein level, as well as the synovial fluid white blood-cell count with differential, are commonly used tests for the diagnosis of periprosthetic joint infection; however, their utility for the diagnosis of periprosthetic joint infection in patients with inflammatory arthritis is unknown. METHODS Eight hundred and three patients undergoing 871 consecutive hip and knee arthroplasties (including sixty-one in patients with inflammatory arthritis and 810 in patients with noninflammatory arthritis) were prospectively evaluated for periprosthetic joint infection. The erythrocyte sedimentation rate, C-reactive protein level, and synovial fluid white blood-cell count with differential were obtained routinely. Receiver operating characteristic curves were used to establish optimal thresholds for the diagnosis of periprosthetic joint infection, and the area under the curve was calculated to determine the overall accuracy of these tests for patients with inflammatory compared with noninflammatory arthritis. RESULTS The utility of all serum and synovial tests for predicting chronic periprosthetic joint infection was similar for patients with noninflammatory and inflammatory arthritis. The optimal cutoffs in patients with noninflammatory and inflammatory arthritis were 32 and 30 mm/hr, respectively, for the erythrocyte sedimentation rate; 15 and 17 mg/L, respectively, for the C-reactive protein level; 3450/μL and 3444/μL, respectively, for the synovial fluid white blood-cell count; and 78% and 75%, respectively, for the differential. The areas under the curves were similar for the two groups (84.9% and 85.0%, respectively, for the erythrocyte sedimentation rate; 88.5% and 85.1%, respectively, for the C-reactive protein level; 94.5% and 93.8%, respectively, for the synovial fluid white blood-cell count, and 95.0% and 93.6%, respectively, for the differential). Finally, the sensitivities, specificities, negative predictive values, and positive predictive values for all tests were also comparable in both groups. The rate of periprosthetic joint infection was significantly higher following procedures in patients with inflammatory arthritis than following procedures in patients with noninflammatory arthritis (31% compared with 18%; p = 0.013). CONCLUSIONS The erythrocyte sedimentation rate, C-reactive protein level, and synovial fluid white blood-cell count with differential are useful for diagnosing periprosthetic joint infection in patients with inflammatory as well as noninflammatory arthritis, with similar optimal cutoff values and overall testing performance. The synovial fluid white blood-cell count and differential performed the best for the diagnosis of periprosthetic joint infection. Physicians evaluating patients with a failed or painful total hip or knee arthroplasty should not assume that elevation of the erythrocyte sedimentation rate, C-reactive protein level, and synovial fluid white blood-cell count with differential is secondary to inflammatory arthropathy; rather, elevation of these markers may indicate periprosthetic joint infection, and further evaluation for infection is warranted.

Dilute Betadine Lavage Before Closure for the Prevention of Acute Postoperative Deep Periprosthetic Joint Infection

This study evaluated the efficacy of a dilute Betadine (Purdue Pharma, Stamford, Conn) lavage in preventing early deep postoperative infection after total hip (THA) and knee (TKA) arthroplasty. A protocol of dilute Betadine lavage (0.35%) for 3 minutes was introduced to the practice of the senior author in June 2008. A total of 1862 consecutive cases (630 THA and 1232 TKA) performed before this were compared with 688 consecutive cases (274 THA and 414 TKA) after for the occurrence of periprosthetic infections within the first 90 days postoperatively. Eighteen early postoperative infections were identified before the use of dilute Betadine lavage, and 1 since (0.97% and 0.15%, respectively; P = .04). There were no significant demographic differences between the 2 groups. Betadine lavage before wound closure may be an inexpensive, effective means of reducing acute postoperative infection after total joint arthroplasty.

Recent Advances Toward the Clinical Application of PTH (1-34) in Fracture Healing

PTH 1-34, an active form of parathyroid hormone, has been shown to enhance osteoblastic bone formation when administered as a daily subcutaneous injection. The effect of the intermittent administration of PTH (1-34) is an uncoupling of bone turnover with an increase in bone mass and density and decrease in risk of vertebral and nonvertebral fractures. While PTH (1-34) has been used clinically to increase bone mass and reduce fracture risk in postmenopausal women with osteoporosis, there is increasing evidence that PTH (1-34) may promote fracture healing. Animal studies have demonstrated accelerated callus formation with enhanced remodeling and biomechanical properties of the healing fracture. Given these effects, PTH (1-34) will likely be used clinically to enhance fracture union in poor healing situations such as osteoporosis and recalcitrant nonunions.

Radiation Therapy for Preventing Recurrence of Neurogenic Heterotopic Ossification

Radiation therapy is commonly used to prevent heterotopic ossification, and the dose-dependent effects of this treatment have been well documented in patients after total hip arthroplasty (THA). However, the efficacy and dose requirement of radiation therapy to prevent heterotopic ossification of nonsurgical origin have not been studied. The purpose of this retrospective case-control study was to determine the effects of prophylactic radiation therapy on severe heterotopic ossification recurrence, postoperative range of motion (ROM), and wound healing in patients with heterotopic ossification secondary to neurologic deficits. Selection was not blinded, and higher risk patients were generally assigned to the treatment group. Standard doses of radiation therapy did not adequately lower recurrence rates; in fact, there was a higher incidence of heterotopic ossification formation necessitating revision in the treatment group (15.0%) compared to the control group (5.1%). Moreover, patients who received radiation therapy were not more successful at maintaining intraoperative ROM over time. There was a similar incidence of delayed wound healing between groups (12.8% in the control group and 12.5% in the treatment group), and no other negative side effects or complications were observed. These results suggest that the 700 cGy dose of radiation therapy typically used for the prophylaxis of heterotopic ossification associated with THA does not effectively prevent the recurrence of neurogenic heterotopic ossification in high-risk patients. Further studies are needed to determine whether higher doses of radiation therapy will provide more effective prophylaxis for heterotopic ossification.

Intra-Operative Periprosthetic Fractures Associated With Press Fit Stems in Revision Total Knee Arthroplasty Incidence, Management, and Outcomes

The purpose of this study is to report the incidence, management, and outcomes of periprosthetic fractures associated with the insertion of press-fit stems during revision total knee arthroplasty (TKA). Immediate and six week post-operative radiographs from 634 stemmed implants (307 femoral, 327 tibial) from 420 consecutive revision TKAs were reviewed. Sixteen tibial (4.9%) and 3 femoral (1%) fractures (combined incidence 3.0%) were identified. All healed uneventfully without operative intervention, with no evidence of implant loosening at a mean of 23 months (range 12 to 47 months). The technique of tightly press fitting stems into the diaphysis is associated with a small rate (3%) of periprosthetic fractures; most were non or minimally displaced, all healed uneventfully with non-operative management and were not associated with implant loosening.

Knee disarticulation and hip release for severe lower extremity contractures

Severe lower extremity contractures cause many problems for patients and their caregivers. Hygiene, skin and perineal care, positioning, and dressing are severely compromised. Surgical management of such deformities is challenging and results have not been published. We treated eight nonambulatory adults with severe and rigid lower extremity contractures with hip release and knee disarticulation of 14 extremities. The patients had neurologic disorders with spasticity. The indications for surgery were fixed contractures of at least 90° at the knee and hip that interfered with passive function and quality of life. All patients were bed-bound secondary to their contractures. The average age at surgery was 57 years; the minimum followup was 6 months (mean, 34 months; range, 6-102 months). The average preoperative flexion contractures were 106° at the hips and 139° at the knees. The average postoperative hip flexion contracture was 6°, and there were no serious complications or recurrent contractures. Positioning and hygiene problems were universally improved, enabling all of the patients to become wheel-chair users, and all patients or their caretakers reported resolution of pain. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

The Clinical Significance of Initial Pulmonary Micronodules in Young Sarcoma Patients.

Background: The clinical significance of subcentimeter nodules identified on staging chest computed tomography (CT) for sarcoma remains unknown. Our goal was to evaluate the effect of initial pulmonary nodule size and number on survival rates in young, newly diagnosed sarcoma patients. Methods: Medical records were reviewed for all patients ⩽50 years of age with primary, high-grade bone or soft tissue sarcoma at our institution over a 10-year period. This population was divided into patients with no nodules (group 1); 1 nodule <5 mm (group 2);>1 nodule <5 mm (group 3); and ≥1 nodule ≥5 mm (group 4). Kaplan-Meier analyses with log rank tests were performed to compare overall and disease-free survival between these 4 groups, as well as between patients with unilateral and bilateral nodules. Results: There were 74 patients in group 1 (59.2%), 26 in group 2 (21%), 11 in group 3 (9%), and 13 in group 4 (10%). Mean follow-up was 74 (range, 6 to 191 mo) months. Survival was only slightly worse with larger nodules but significantly worse with multiple nodules. In addition, patients with bilateral nodules had a significantly worse prognosis than those with multiple unilateral nodules. Conclusions: These data suggest that in young patients with high-grade sarcoma, the number and distribution of subcentimeter pulmonary nodules are an important prognostic factor, whereas nodule size may be less relevant.

Use of the Reamer–Irrigator–Aspirator May Reduce Tumor Dissemination During Intramedullary Fixation of Malignancies

Intramedullary nail fixation is the treatment of choice for impending and pathologic fractures secondary to metastatic cancer; however, this procedure has been shown to cause systemic embolization of intramedullary contents. This article reports the use of the reamer-irrigator-aspirator (RIA) (Synthes, Paoli, Pennsylvania) instead of a standard femoral reamer to decrease tumor intravasation during femoral intramedullary nail fixation for impending or pathologic fractures.Twenty-one consecutive patients indicated for fixation of malignant femoral lesions were treated with intramedullary nail placement. The RIA was used for canal preparation, and solid reamings were collected and submitted for analysis by a single pathologist. The volume of each specimen was recorded, and representative samples were examined histologically to determine their percent tumor content. These data were then used to estimate the volume of tumor retrieved by the RIA in each case. The mean volume of reamings collected by the RIA was 75.0 cc per case (range, 23.4-196.0 cc), and the mean tumor content was 24.8% (range, 1.0%-60.0%). The mean estimated volume of tumor retrieved in each case was 16.7 cc (range, 0.35-36.0 cc). In 2 cases, the tip of the RIA dissociated from the device intraoperatively but was retrieved without adverse consequence to the patient. Use of the RIA in cases of femoral intramedullary nail fixation for pathologic lesions or fractures effectively retrieves variable amounts of intramedullary contents, including tumor. By preventing the systemic dissemination of malignant cells, this technique may reduce the risk of distant metastases.

Giant Cell Tumor with Involvement of the Patellar Ligament

We report a clinically, radiographically, and pathologically definite case ofa giant cell tumor (GCT) of bone arising in the tibial tuberosity. To our knowledge, this represents the first reported case ofa GCT of bone in this location. Due to involvement of the patellar ligament, the defect was not filled with methylmethacrylate; instead, bone grafting was performed to promote healing. GCT needs to be considered in the differential diagnosis of a lytic lesion of the tibial tuberosity.