Retrograde Intramedullary Nailing Versus Locked Plating for Extreme Distal Periprosthetic Femur Fractures: A Multicenter Retrospective Cohort Study.

OBJECTIVES: To compare clinical and radiographic outcomes after retrograde intramedullary nailing (rIMN) versus locked plating (LP) of "extreme distal" periprosthetic femur fractures, defined as those that contact or extend distal to the anterior flange. DESIGN: Retrospective review. SETTING: Eight academic level I trauma centers. PATIENT SELECTION CRITERIA: Adult patients with periprosthetic distal femur fractures at or distal to the anterior flange (OTA/AO 33B-C[VB1]) treated with rIMN or LP. OUTCOME MEASURES AND COMPARISONS: The primary outcome was reoperation to promote healing or to treat infection (reoperation for elective removal of symptomatic hardware was excluded from this analysis). Secondary outcomes included nonunion, delayed union, fixation failure, infection, overall reoperation rate, distal femoral alignment, and ambulatory status at final follow-up. Outcomes were compared between patients treated with rIMN or LP. RESULTS: Seventy-one patients treated with rIMN and 224 patients treated with LP were included. The rIMN group had fewer points of fixation in the distal segment (rIMN: 3.5 ± 1.1 vs. LP: 6.0 ± 1.1, P < 0.001) and more patients who were allowed to weight-bear as tolerated immediately postoperatively (rIMN: 45%; LP: 9%, P < 0.01). Reoperation to promote union and/or treat infection was 8% in the rIMN group and 16% in the LP group ( P = 0.122). There were no significant differences in nonunion ( P > 0.999), delayed union ( P = 0.079), fixation failure ( P > 0.999), infection ( P = 0.084), or overall reoperation rate ( P > 0.999). Significantly more patients in the rIMN group were ambulatory without assistive devices at final follow-up (rIMN: 35%, LP: 18%, P = 0.008). CONCLUSIONS: rIMN of extreme distal periprosthetic femur fractures has similar complication rates compared with LP, with a possible advantage of earlier return to weight-bearing. Surgeons can consider this treatment strategy in all fractures with stable implants and amenable prosthesis geometry, even extreme distal fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Early prediction of tibial and femoral fracture healing: Are we reliable?

INTRODUCTION: To evaluate the ability of orthopaedic trauma subspecialists to predict early bony union in femoral and tibia shaft fractures. MATERIALS AND METHODS: Eight orthopaedic trauma subspecialists prospectively predicted the probability of bony union at 6 and 12 weeks post-operatively for an aggregate of 48 femoral and tibial shaft fractures treated at a Level 1 trauma centre. An additional orthopaedic trauma subspecialist was blinded to treating surgeon and adjudicated healing at 18 weeks. The Squared-Error Skill Score (SESS) determined the likelihood of accurate forecasting for bony union. RESULTS: Nine patients were lost follow-up, resulting in 39 fractures (81.25% retention) including 20 femoral and 19 tibial fractures. Fourteen fractures were open, 15 were not-yet united at final follow-up. SESS values were 0.25-0.77. The ability to predict union (sensitivity) was 1.000. The ability to predict nonunions (specificity) was 0.330-0.500. The probability of a correct predicted union was 0.727 and correct predicted nonunion at final follow-up was 1.000. AO/OTA type A fractures pattern predictions were highly accurate. As body mass index increased, predictions trended toward decreased accuracy (p=0.06). Tobacco use, age, gender, associated injuries, open fractures, and surgeons' years in clinical practice were not associated with accuracy of predictions. CONCLUSIONS: At 12-weeks post-operatively orthopaedic trauma subspecialists can confidently predict the union state in this patient population. This data is most useful in the nonunion patient, directing early intervention, thereby decreasing patient disability and discomfort.

Buttress Plating Versus Anterior-to-Posterior Lag Screws for Fixation of the Posterior Malleolus: A Biomechanical Study.

OBJECTIVES: The preferred method of fixation for posterior malleolus fractures remains controversial, and practices vary widely among surgeons. The purpose of this study was to compare anterior-to-posterior (AP) lag screws with posterior buttress plating for fixation of posterior malleolus fractures in a human cadaveric model. METHODS: Posterior malleolus fractures involving 30% of the distal tibial articular surface were created in 7 pairs of fresh frozen cadaveric ankles. One specimen in each pair was randomly assigned to fixation with either 2 AP lag screws or a one-third tubular buttress plate without supplemental lag screws. Each specimen was then subjected to cyclic loading from 0% to 50% of body weight for 5000 cycles followed by loading to failure. Outcome measures included permanent axial displacement during each test cycle (axial displacement at no load), peak axial displacement during each test cycle (axial displacement at 50% body weight), load at 1-mm axial displacement, ultimate load, and axial displacement at ultimate load. RESULTS: The buttress plate group showed significantly less peak axial displacement at all time points during cyclic loading. Permanent axial displacement was significantly less in the buttress plate group beginning at cycle 200. There were no significant differences between the 2 groups during load-to-failure testing. CONCLUSION: Posterior malleolus fractures treated with posterior buttress plating showed significantly less displacement during cyclical loading compared with fractures fixed with AP lag screws. Surgeons should consider these findings when selecting a fixation strategy for these common fractures. Further research is warranted to investigate the clinical implications of these biomechanical findings.

Open reduction and intramedullary nail fixation of closed tibial fractures.

Some tibial shaft fractures cannot be accurately reduced using closed or percutaneous techniques during an intramedullary nailing procedure. Under these circumstances, a formal open reduction can be performed. Direct exposure of the fracture facilitates accurate reduction but does violate the soft tissue envelope. The purpose of this study was to evaluate the safety and efficacy of open reduction prior to intramedullary nailing. Using the trauma database at a Level I trauma center, 11 uncomplicated closed displaced tibia fractures treated with formal open reduction prior to intramedullary nailing were identified and matched with a cohort of 21 fractures treated with closed reduction and nailing. The authors attempted to match 2 controls to each patient to improve the power of the study. Clinical and radiographic outcomes were compared. All fractures ultimately healed within 5° of anatomic alignment. No infections or non-unions occurred in the open reduction group, and 1 deep infection and 1 nonunion occurred in the closed reduction group. No significant differences existed between the study groups. Although closed reduction and intramedullary nailing remains the treatment of choice for most significantly displaced tibial shaft fractures, open reduction with respectful handling of the soft tissue envelope can be safe and effective and should be considered when less invasive techniques are unsuccessful.

Normal tibiofibular relationships at the syndesmosis on axial CT imaging.

OBJECTIVES: Computed tomography (CT) is reported to be superior to plain radiography for imaging the syndesmosis, but CT criteria differentiating normal from abnormal tibiofibular relationships do not exist. The purpose of this study was to define normal tibiofibular relationships at the syndesmosis on axial CT imaging and to report the reliability of these measurements. METHODS: Thirty healthy volunteers underwent CT evaluation of bilateral ankles. Axial CT measurements consisted of tibiofibular clear space, tibiofibular overlap, anterior tibiofibular interval, and fibular rotation (θ(fib)). To assess reliability, 3 investigators independently made each CT measurement on 2 separate occasions. RESULTS: Sixty ankles were included for analysis. CT measurements demonstrated excellent intrarater and interrater reliability. There was significant anatomic variability between individuals. Specifically, statistically significant gender differences were discovered in CT measurements of tibiofibular overlap and anterior tibiofibular interval. Variance between ankles of each subject was calculated. In an uninjured population, tibiofibular intervals do not vary by more than 2.3 mm, and the rotation of the fibula does not vary by more than 6.5° between ankles of the same person. CONCLUSIONS: Measurements of tibiofibular relationships made on axial CT images are reliable. Because of significant anatomic variation between individuals, using a patient's contralateral ankle for comparison provides a precise definition of normal tibiofibular relationships. These criteria allow for the detection of subtle variations in the tibiofibular relationships indicating instability and provide a tool for postoperatively assessing the reduction of the injured syndesmosis.

Rotational alignment in total knee arthroplasty: intraoperative inter- and intraobserver reliability of Whiteside's line.

INTRODUCTION: Proper rotational alignment is a critical step of total knee arthroplasty. For intraoperative determination of femoral rotation, Whiteside suggests a perpendicular line to the axis of the center of the trochlea and the intercondylar notch (Whiteside's line). METHOD: In a prospective clinical study, the intraoperative position of Whiteside's line was measured in 30 patients with the help of a navigation system. RESULTS: Whiteside's line was 2.1° ± 1.5° externally rotated compared to a navigation based computer calculated preliminary AP axis of the femur. The intraobserver-reliability after 3 repeated measurements each was 1.6° for the senior surgeon and 1.4° for the junior surgeon (p = 0.598, p = 0.968). The interobserver reliability between the measurements by the senior and junior surgeon was 1.4° (p = 0.547). CONCLUSION: Navigated intraoperative measurements of Whiteside's line showed a high inter- and intraobserver reliability. Considering the variability between Whiteside's line and the transepicondylar axis, intraoperative assessment of both the methods is recommended.

Long-term lower extremity prosthetic costs in children with traumatic lawnmower amputations.

OBJECTIVES: To evaluate prosthetic costs of pediatric lawnmower amputations; to see if reducing the incidence of pediatric lawnmower amputations could result in significant cost savings; and to consider if a cost analysis could be useful to implement more safety features (voluntarily or legislatively). DESIGN: Pediatric lawnmower amputees from 1980 to 2000 were reviewed to determine age at time of injury, level of amputation, number of prostheses, and lifetime per prosthesis. A standard prosthetic program beginning at amputation and ending at age 18 years was constructed. An aggregate cost was calculated according to the proportion of amputation levels. The cost burden for prosthetic care was estimated from the statistics of US pediatric lawnmower injuries. SETTING: Referral pediatric orthopedic center. PATIENTS: Fifty-three lower extremity amputees with 58 lower extremity amputations at a mean +/- SD age of 4.7 +/- 2.5 years were reviewed. RESULTS: The percentage of amputee children injured by riding lawnmowers was 80%; the percentage injured by riding lawnmowers engaged in reverse was 39%. Prosthetic costs from the time of injury to the age of 18 years range from 73,140 dollars to 116,040 dollars per single lower extremity amputation. With 600 to 650 new childhood amputations per year due to lawnmowers, the new annual burden for prosthetic costs thus ranges from 43.88 to 75.42 million dollars, or (600)(73,140 dollars) to (650)(116,040 dollars). CONCLUSIONS: Further encouragement of lawnmower manufacturers to install improved safety devices (such as those to disengage power while in reverse mode of operation), new research on improved safety measures, and continued promotion of educational campaigns regarding the dangers of children being around and/or operating riding lawnmowers and garden tractors should be pursued. This will result in significant cost savings as well as incalculable health savings.