Effects of teriparatide on fusion rates in patients undergoing complex foot and ankle arthrodesis.

BACKGROUND: Here, we determined whether teriparatide treatment would increase fusion rates after foot and ankle arthrodesis by comparing treatment results between patients with high-risk factors for nonunion who received teriparatide against those who did not. METHODS: We retrospectively reviewed 66 consecutive patients who underwent foot and ankle arthrodesis. The inclusion criterion was the presence of at least one of the following risk factors for nonunion after previous foot and ankle arthrodesis: deformity, bone defects, avascular necrosis, and nonunion. Sixteen patients were finally enrolled and divided into 2 groups: 8 patients received teriparatide treatment after fusion surgery (PTH group), and 8 patients did not (control group). RESULTS: The fusion rate was significantly greater in the PTH group than in the control group (100% vs 50%). Four patients in the control group developed nonunion, 3 of whom underwent revision fusion; however, all patients received the teriparatide treatment after revision surgery and subsequently achieved union. No significant differences in demographics, fusion sites, and complication rates were found. CONCLUSION: Though the sample size was small, the current study suggests that teriparatide administration may improve fusion rates in patients with high-risk factors for nonunion after foot and ankle arthrodesis.

Unicompartmental knee arthroplasty fails to completely restore normal gait patterns during level walking.

PURPOSE: Gait analysis is a valuable instrument for measuring function objectively after unicompartmental knee arthroplasty (UKA). However, most gait analysis studies have reported conflicting results for functional assessment after UKA. This meta-analysis compared the gait patterns of UKA patients and healthy controls during level walking. METHODS: Studies were included in the meta-analysis if they recorded vertical ground reaction force (GRF), flexion at initial contact, flexion at loading response, extension at mid-stance, flexion at swing, walking speed, cadence, and stride length in UKA patients or healthy controls. RESULTS: Seven studies met the criteria for inclusion in the meta-analysis. The UKA patients and healthy controls were similar in terms of vertical GRF (95% CI - 0.54 to 0.23; ns), flexion at initial contact (95% CI - 0.47 to 4.96; ns), flexion at loading response (95% CI - 1.29 to 3.69; ns), and flexion at swing (95% CI - 8.85 to 0.40; ns). In contrast, extension at mid-stance (95% CI 0.53 to 4.88; P = 0.01), walking speed (95% CI - 2.13 to - 0.15; P = 0.02), cadence (95% CI - 1.02 to - 0.25; P = 0.001), and stride length (95% CI - 2.02 to - 0.22; P = 0.01) differed significantly between groups. Subgroup analyses revealed that the pooled data were similar between groups: 1st maximum (heel strike), - 0.43 BW (ns); 1st minimum (mid-stance), 0.61 BW (ns); and 2nd maximum (toe off), - 0.46 BW (ns). CONCLUSIONS: There were no significant differences in vertical GRF or overall kinematics in the sagittal plane between UKA patients and healthy controls during level walking. However, the UKA group had a significantly slower walking speed and cadence and a shorter stride length than healthy controls. The current findings suggest that, clinically, UKA fails to completely restore normal gait patterns. LEVEL OF EVIDENCE: Level II, therapeutic study.

Diagnostic accuracy of interleukin-6 and procalcitonin in patients with periprosthetic joint infection: a systematic review and meta-analysis.

PURPOSE: Many studies have found associations between laboratory biomarkers and periprosthetic joint infection (PJI), but it remains unclear whether these biomarkers are clinically useful in ruling out PJI. This meta-analysis compared the performance of interleukin-6 (IL-6) versus procalcitonin (PCT) for the diagnosis of PJI. METHODS: In this meta-analysis, we reviewed studies that evaluated IL-6 or/and PCT as a diagnostic biomarker for PJI and provided sufficient data to permit sensitivity and specificity analyses for each test. The major databases MEDLINE, EMBASE, the Cochrane Library, Web of Science, and SCOPUS were searched for appropriate studies from the earliest available date of indexing through February 28, 2017. No restrictions were placed on language of publication. RESULTS: We identified 18 studies encompassing a total of 1,835 subjects; 16 studies reported on IL-6 and 6 studies reported on PCT. The area under the curve (AUC) was 0.93 (95% CI, 0.91-0.95) for IL-6 and 0.83 (95% CI, 0.79-0.86) for PCT. The pooled sensitivity was 0.83 (95% CI, 0.74-0.89) for IL-6 and 0.58 (95% CI, 0.31-0.81) for PCT. The pooled specificity was 0.91 (95% CI, 0.84-0.95) for IL-6 and 0.95 (95% CI, 0.63-1.00) for PCT. Both the IL-6 and PCT tests had a high positive likelihood ratio (LR); 9.3 (95% CI, 5.3-16.2) and 12.4 (95% CI, 1.7-89.8), respectively, making them excellent rule-in tests for the diagnosis of PJI. The pooled negative LR for IL-6 was 0.19 (95% CI, 0.12-0.29), making it suitable as a rule-out test, whereas the pooled negative LR for PCT was 0.44 (95% CI, 0.25-0.78), making it unsuitable as a rule-out diagnostic tool. CONCLUSIONS: Based on the results of the present meta-analysis, IL-6 has higher diagnostic value than PCT for the diagnosis of PJI. Moreover, the specificity of the IL-6 test is higher than its sensitivity. Conversely, PCT is not recommended for use as a rule-out diagnostic tool.

Occult periprosthetic femoral fractures occur frequently during a long, trapezoidal, double-tapered cementless femoral stem fixation in primary THA.

The present study aimed to investigate the prevalence and clinical consequences of occult intra-operative periprosthetic femoral fractures in total hip arthroplasty (THA). Between 2012 and 2017, a total of 113 primary THAs were enrolled. The mean age of the patients was 66.4 ± 7.6 years. We assessed occult intra-operative periprosthetic femoral fractures with the use of computed tomography (CT) and risk factors, including age, sex, body mass index, diagnosis, stem size, and radiographic parameters of proximal femoral geometry were analyzed. We also assessed the differences in thigh pain and stem subsidence and alignment between the patients with and without occult periprosthetic femoral fracture. Occult intra-operative periprosthetic femoral fractures were found in 13 of 113 hips (11.5%). In 9/13 (69.2%) of occult fractures, fracture lines were started from the region below the tip of the lesser trochanter. Six periprosthetic femoral fractures (5.3%) were found during the operation. Out of the five hips that had detected femoral fractures around the lesser trochanter intra-operatively, four hips (80%) showed concurrent occult fractures on different levels. The female sex (P = .01) and canal filling ratio at 7 cm below the tip of the lesser trochanter (P = .01) were significantly different between the patients with and without occult periprosthetic femoral fracture. The sex was significantly associated with an increased risk in predicting an occult intra-operative periprosthetic femoral fracture (odds ratio of male, 0.25 compared with the female; 95% CI, 0.08-0.85; p = .02). There was a significant difference in the incidence of thigh pain between occult fracture group and non-occult fracture group (P < .05). There were no significant differences in stem subsidence and alignment between the patients with and without occult periprosthetic femoral fracture. All 13 cases of occult intra-operative periprosthetic femoral fractures were healed at the final follow-up. Occult periprosthetic femoral fractures are common during a long, trapezoidal, double-tapered cementless femoral stem fixation in primary THA, that CT scans are helpful to identify them, and that these fractures do not adversely affect the implant's survival if a rigid fixation of the implants has been achieved.