Use of the SIGN IM nail system to stabilize tibiotalocalcaneal arthrodesis in two African hospital settings.

OBJECTIVES: To determine the effectiveness and describe the technique of using the Surgical Implant Generation Network (SIGN) nail to augment tibiotalocalcaneal (TTC) arthrodesis in the developing world. DESIGN: Retrospective review of the SIGN database and description of surgical technique. SETTING: Two centers in rural Kenya, East Africa. PATIENTS: Fifty-seven patients with ankle/hindfoot arthritis or severe trauma. We were able to follow 17 through complete arthrodesis. INVENTION: TTC arthrodesis stabilized with SIGN nail. MAIN OUTCOME MEASURE: Radiographic arthrodesis and return to function. RESULT: Of the patients with significant follow-up, arthrodesis occurred in an average of 19.3 ±â€Š7.5 weeks from the date of surgery. CONCLUSIONS: Recognizing the obstacles to follow-up, the SIGN nail placed with the Herzog curve apex posterior is shown to be an effective device to stabilize a TTC arthrodesis in a limited subgroup of patients with full follow-up.

Risk Factors for Infection After Intramedullary Nailing of Open Tibial Shaft Fractures in Low- and Middle-Income Countries.

OBJECTIVES: (1) To determine the infection rate after fixation of open tibial shaft fractures using the Surgical Implant Generation Network (SIGN) intramedullary nail in low- and middle-income countries (LMICs) and (2) to identify risk factors for infection. DESIGN: Prospective cohort study using an international online database. SETTING: Multiple hospitals in LMICs worldwide. PATIENTS/PARTICIPANTS: A total of 1061 open tibia fractures treated with the SIGN nail in LMICs between March 2000 and February 2013. INTERVENTION: Intravenous antibiotic administration, surgical debridement, and definitive intramedullary nailing within 14 days of injury. MAIN OUTCOME MEASUREMENTS: Deep or superficial infection at follow-up, implant breakage/loosening, angular deformity >10 degrees, repeat surgery, radiographic union, weight bearing, and ability to kneel. RESULTS: The overall infection rate was 11.9%. Infection rates by the Gustilo and Anderson classification were type 1: 5.1%, type II: 12.6%, type IIIa: 12.5%, type IIIb: 29.1%, and type IIIc: 16.7% (P = 0.001 between groups). Patients who developed infection had a longer mean time from injury to definitive surgery (4.7 vs. 3.9 days, P = 0.03) and from injury to wound closure (13.7 vs. 3.6 days, P < 0.001). Distal fractures had a higher infection rate than midshaft fractures (13.3% vs. 8.2%, P = 0.03). Infection rates were not associated with time from injury to initial debridement, time from injury to initial antibiotic administration, or total duration of antibiotics. CONCLUSIONS: Open tibia fractures can be managed effectively using the SIGN intramedullary nail in LMICs with an overall infection rate of 11.9%. Risk factors for infection identified include more severe soft-tissue injury, delayed nailing, delayed wound closure, and distal fracture location. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Satisfactory postoperative alignment following retrograde SIGN Fin nailing for femoral shaft fractures: A case-control study.

PURPOSE: In developing countries, long bone fractures following trauma are a significant contributor to morbidity, and operating room resources are often limited in these settings. The Surgical Implant Generation Network (SIGN) Fin nail may reduce the challenges of retrograde intramedullary nailing of femoral fractures without fluoroscopy. In contrast to the traditional SIGN nail placed in a retrograde fashion, the Fin nail does not require proximal interlocking screws. Instead, the nail achieves stability through an interference fit within the proximal femoral canal. The purpose of this study is to compare postoperative alignment in femoral shaft fractures treated with either a retrograde SIGN Fin nail or a standard retrograde SIGN nail. METHOD: Using the SIGN online surgical database, we identified all femoral shaft fractures treated with a retrograde SIGN Fin nail at 2 African hospitals. Two examiners independently classified fracture patterns using the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) classification system. Using an on-screen protractor tool, postoperative coronal and sagittal plane alignment were measured and recorded as deviation from anatomic alignment (DFAA), with units in degrees. Available patient demographics and surgical details were also recorded. Fin nail cases were matched in a 1:1 ratio to retrograde standard SIGN nail cases based on AO/OTA fracture type. RESULTS: Twenty-eight retrograde Fin nail cases were identified, and 28 matched retrograde SIGN nail cases were selected. The Fin nail and retrograde SIGN nail groups were well matched in terms of demographics, AO/OTA fracture type, and surgical characteristics. There was no significant difference in postoperative coronal or sagittal plane alignment between the groups. There were no cases in either group of average postoperative malalignment >5° in any plane. CONCLUSION: The SIGN Fin nail appears to achieve satisfactory radiographic alignment without the need for proximal interlocking screws, making it an attractive implant for retrograde femoral shaft fracture fixation in resource-limited settings. Further research is required to validate these findings and determine long-term Fin nail clinical outcomes.

Synovial chondromatosis of the foot and ankle.

BACKGROUND: Synovial chondromatosis (SC) is a benign condition where the synovial lining of joints, bursae, or tendon sheaths undergoes metaplasia and ultimately forms cartilaginous loose bodies. Synovial chondromatosis of the foot and ankle is exceedingly rare, and outcomes following surgical excision are largely unknown. MATERIALS AND METHODS: An Institutional Review Board-approved retrospective review of our institution's surgical database from 1970 to 2006 revealed 8 patients with SC of the foot and/or ankle confirmed by pathology. RESULTS: Eight patients (4 female and 4 male) presented with pain, locking, or stiffness. Average age at presentation was 37 (range, 19 to 60) years. Average followup was 9.5 (range, 1 to 31) years. Six patients had involvement of the ankle, and two, the midfoot. Four patients underwent ankle synovectomy with loose body removal, and were pain-free at last followup. One patient underwent excision and midfoot arthrodesis for severe midfoot destruction. Three patients ultimately underwent below knee amputation, one for multiple recurrences and two for malignant transformation to low-grade chondrosarcoma. CONCLUSION: To our knowledge, this is the largest reported series of patients with SC of the foot and ankle. In half the patients, synovectomy with excision of loose bodies resulted in pain free return to normal function, without recurrence, at last followup. However, recurrence occurred in 3 (37.5%) of 8 patients with subsequent malignant transformation to low-grade chondrosarcoma occurring in 2 patients.

State of Pelvic and Acetabular Surgery in the Developing World: A Global Survey of Orthopaedic Surgeons at Surgical Implant Generation Network (SIGN) Hospitals.

OBJECTIVES: To document the current state of pelvic and acetabular surgery in the developing world and to identify critical areas for improvement in the treatment of these complex injuries. DESIGN: A 50-question online survey. SETTING: International, multicenter. PATIENTS/PARTICIPANTS: One hundred eighty-one orthopaedic surgeons at Surgical Implant Generation Network (SIGN) hospitals, which represent a cross-section of institutions in low- and middle-income countries that treat high-energy musculoskeletal trauma. INTERVENTIONS: Administration and analysis of 50-question survey. MAIN OUTCOME MEASURES: Surgeon training and experience; hospital resources; volume and patterns of pelvic/acetabular fracture management; postoperative protocols and resources for rehabilitation; financial responsibilities for patients with pelvic/acetabular fractures. RESULTS: Complete surveys were returned by 75 institutions, representing 61.8% of the global SIGN nail volume. Although 96% of respondents were trained in orthopaedic surgery, 53.3% have no formal training in pelvic or acetabular surgery. Emergency access to the operating room is available at all responding sites, but computed tomography scanners are available at only 60% of sites, and a mere 21% of sites have access to angiography for pelvic embolization. Cannulated screws (53.3%) and pelvic reconstruction plates (56%) are available at just over half of the sites, and 68% of sites do not have pelvic reduction clamps and retractors. 21.3% of sites do not have access to intraoperative fluoroscopy. Responding hospitals see an average of 38.8 pelvic ring injuries annually, with 24% of sites treating them all nonoperatively. Sites treated an average of 22.5 acetabular fractures annually, with 34.7% of institutions treating them all nonoperatively. Patients travel up to 1000 km or 20 hours for pelvic/acetabular treatment at some sites. Although 78.7% of sites have inpatient physical or occupational therapy services, only 17% report access to home physical therapy, and only 9% report availability of nursing or rehabilitation facilities postdischarge. At over 80% of hospitals, patients and their families are at least partially responsible for payment of surgical, implant, hospital, and outpatient fees. Government aid is available for inpatient fees at over 40% of sites, but outpatient services are subsidized at only 28% of sites. CONCLUSIONS: We report the current state of pelvic and acetabular surgery in low- and middle-income countries. Our results identify significant needs in surgeon training, hospital resources, availability of instruments and implants, and access to appropriate postoperative rehabilitation services for pelvic and acetabular surgery in the developing world. Targeted programs designed to overcome these barriers are required to advance the care of pelvic and acetabular fractures in the developing world.

Correlation of compartment pressure data from an intraoperative sensing device with postoperative fluoroscopic kinematic results in TKA patients.

Fluoroscopy has recently been used to analyze postoperative kinematics in total knee arthroplasty (TKA). These analyses have reported varying results even in patients with similar implant design. In addition, patterns of wear in retrieved tibial polyethylene inserts of similar design have been found to vary substantially. These findings suggest that surgical technique, especially soft tissue balancing, may play a role in postoperative kinematics and implant failure. Accurate soft-tissue balancing is hypothesized to result in similar pressures within the medial and lateral compartments of the knee. However, a method of easily measuring these pressures at TKA has not been developed. In the present study, 32 patients were implanted with a mobile-bearing LCS TKA utilizing the balanced gap technique. An electronic pressure sensor, developed specifically to record pressure magnitude and distribution in the medial and lateral compartments, was incorporated into the implant trials. The knee was then passively taken through a range of motion while pressure data was recorded via computer. Postoperatively, 16 patients underwent active fluoroscopic kinematic analysis to assess for condylar liftoff and femorotibial translation. We found that abnormal compartment pressures and distributions as recorded by the intraoperative pressure sensor were correlated with inappropriate or paradoxical postoperative kinematics. In addition, subjects having similar pressures in both compartments throughout a range of motion did not experience condylar liftoff values greater than 1.0 mm. These data suggest that surgical technique influences the magnitude and distribution of forces at the articulation, postoperative kinematics, and likely, implant longevity.

Surgical treatment of early wound complications following primary total knee arthroplasty.

BACKGROUND: Wound-healing problems are a known complication after primary total knee arthroplasty. However, little is known about the clinical outcomes for patients who require surgical treatment of these early wound-healing problems. The purpose of the present study was to determine the incidence, risk factors, and long-term sequelae of early wound complications requiring surgical treatment. METHODS: The total joint registry at our institution was reviewed for the period from 1981 to 2004. All knees with early wound complications necessitating surgical treatment within thirty days after the index total knee arthroplasty were identified. The cumulative probabilities for the later development of deep infection and major subsequent surgery were determined. A case-control study in which these patients were matched with an equal number of controls was performed to attempt to identify risk factors for the development of early superficial wound complications requiring surgical intervention. RESULTS: From 1981 to 2004, 17,784 primary total knee arthroplasties were performed at our institution. Fifty-nine knees were identified as having early wound complications necessitating surgical treatment within thirty days after the index arthroplasty, for a rate of return to surgery of 0.33%. For knees with early surgical treatment of wound complications, the two-year cumulative probabilities of major subsequent surgery (component resection, muscle flap coverage, or amputation) and deep infection were 5.3% and 6.0%, respectively. In contrast, for knees without early surgical intervention for the treatment of wound complications, the two-year cumulative probabilities were 0.6% and 0.8%, respectively (p < 0.001 for both comparisons). A history of diabetes mellitus was identified as being significantly associated with the development of early wound complications requiring surgical intervention. CONCLUSIONS: Patients requiring early surgical treatment for wound-healing problems after primary total knee arthroplasty are at significantly increased risk for further complications, including deep infection and/or major subsequent surgery, specifically, resection arthroplasty, amputation, or muscle flap coverage. These results emphasize the importance of obtaining primary wound-healing after total knee arthroplasty.

Early return to surgery for evacuation of a postoperative hematoma after primary total knee arthroplasty.

BACKGROUND: Development of a postoperative hematoma is a reported complication after primary total knee arthroplasty. However, little is known about the clinical outcomes in patients who require surgical evacuation of an acute hematoma. The purpose of this study was to determine the incidence, risk factors, and long-term sequelae of postoperative hematomas requiring surgical evacuation. METHODS: From 1981 to 2004, 17,784 primary total knee arthroplasties were performed at our institution. Forty-two patients (forty-two knees) returned to the operating room within thirty days of the index arthroplasty for evacuation of a postoperative hematoma. A case-control study, with forty-two patients matched one-to-one with forty-two control subjects, was performed to attempt to identify risk factors for the development of postoperative hematoma requiring surgical evacuation. RESULTS: The rate of return to surgery within thirty days for evacuation of a postoperative hematoma was 0.24% (95% confidence interval, 0.17% to 0.32%). For patients undergoing postoperative hematoma evacuation, the two-year cumulative probabilities of undergoing subsequent major surgery (component resection, muscle flap coverage, or amputation) or having a deep infection develop were 12.3% (95% confidence interval, 1.6% to 22.4%) and 10.5% (95% confidence interval, 0.2% to 20.2%), respectively. In contrast, for knees without early hematoma evacuation, the two-year cumulative probabilities were 0.6% (95% confidence interval, 0.5% to 0.7%) and 0.8% (95% confidence interval, 0.6% to 0.9%), respectively (p < 0.001 for both outcomes). A history of a bleeding disorder was identified as having a significant association with the development of a hematoma requiring surgical evacuation (p = 0.046). CONCLUSIONS: Patients who return to the operating room within thirty days after the index total knee arthroplasty for evacuation of a postoperative hematoma are at significantly increased risk for the development of deep infection and/or undergoing subsequent major surgery. These results support all efforts to minimize the risk of postoperative hematoma formation.

Results of total hip and total knee arthroplasties in patients with synovial chondromatosis.

This retrospective analysis examines the outcome of total joint arthroplasty for severe arthritis in patients with synovial chondromatosis. All 11 patients treated with total hip arthroplasty (n = 7) or total knee arthroplasty (n = 4) returned for follow-up at a mean of 10.8 years after surgery. Pain and functional scores improved significantly in all patients. Knee range of motion improved in all patients. Synovial chondromatosis recurred in 1 knee (25%) and 1 hip (14%). Total joint arthroplasty is a valuable treatment option for these patients with predictable improvement in pain and function. Knee range of motion is likely to improve but may be less than expected for primary total knee arthroplasty. Patients remain at risk for recurrence.

Acetabular anatomy and transacetabular screw fixation at the high hip center.

A quadrant system that defines the safe acetabular locations for screw placement exists for the anatomic hip center. We wanted to develop a similar system for the high hip center. The purposes of our study were to identify the anatomic structures at risk during placement of transacetabular screws in the high hip center, to identify maximum bone depth for screw purchase, and to determine if a high hip center quadrant system could be validated to guide placement of screws during acetabular arthroplasty. For this cadaver study of nine pelves, an acetabulum was reamed superiorly into the high hip center a distance equal to (1/2) of the native acetabular diameter. Screws exiting the acetabular bone by 15 mm were inserted before a computed tomography scan and a precise anatomic dissection were done. Structures at risk of penetration by screws include the external iliac vessels, the obturator nerve and vessels, the superior gluteal nerve and vessels, and the sciatic nerve. We found that a quadrant system at the high hip center can demarcate safe zones for screw placement. At the high hip center, only the peripheral (1/2) of the posterior quadrants are safe for screw placement.

An intraoperative pressure-measuring device used in total knee arthroplasties and its kinematics correlations.

Fluoroscopic and retrieval analyses of knee implants show considerable variability even for the same implant design, and implicate the possible importance of surgical technique and compartment pressure balance in total knee arthroplasties. This study was done to correlate intraoperative computer-assessed compartment pressure measurements with postoperative kinematics to explain these variations. Thirty-eight patients had posterior cruciate-sacrificing low-contact stress total knee arthroplasties using a balanced gap technique. At trial reduction, an instrumented tibial insert designed to record the magnitude, location, and dynamic imprint of the pressures in the medial and lateral compartments was placed into the knee. Pressures were recorded electronically for a range of motion from 0 degrees - 120 degrees. Sixteen of the 38 patients agreed to do successive weightbearing deep knee bends under fluoroscopic surveillance. Only three of the 16 patients had condylar lift-off, but all experienced lift-off at a single flexion angle. In the three patients who had condylar lift-off, a compartment pressure imbalance, as measured by the intraoperative pressure sensor, occurred at the same flexion angle of lift-off. These data suggest that although a given implant design may have inherent kinematic tendencies, surgical technique and compartment pressure balance significantly impact kinematic performance.

Radiographic evaluation of screw position in revision total hip arthroplasty.

Injury to intrapelvic structures during removal of screws in revision acetabular arthroplasty is an uncommon, yet potentially serious complication. Bicortical screws are at greatest risk for causing injury during removal, especially if directed toward intrapelvic vessels and nerves. Complications can be minimized with thorough evaluation of screw position before revision surgery. A study of seven cadaveric pelves was done to determine if plain radiographic views provide useful information regarding screw position. In each pelvis, bicortical transacetabular screws were fixed in all acetabular quadrants 15 mm longer than the measured depth. Afterward, anteroposterior, inlet, Judet, and cross-table lateral radiographic views were obtained and intrapelvic dissections were done. Radiographs and intrapelvic dissections were compared to determine screw position. We found that the obturator and iliac oblique (Judet) views were most useful in defining screw position. The iliac oblique view clearly revealed screws that violated the quadrilateral surface and therefore were directed toward the obturator vessels and nerve. The obturator oblique view revealed screws that violated the anterior column and therefore were directed toward the external iliac vessels. The lateral view additionally clarified such screws by determining general anterior or posterior direction.