Long-Term Outcomes Following Single-Stage Reamed Intramedullary Exchange Nailing in Apparently Aseptic Femoral Shaft Nonunion with Unsuspected Proof of Bacteria.

Background: The aim of this study was to evaluate detection rates and risk factors for unsuspected proof of bacteria, as well as clinical and radiologic outcomes following femoral shaft nonunion without clinical signs of infection treated by a single-stage surgical revision procedure including reamed intramedullary exchange nailing. Methods: A retrospective cohort study was performed in a European level I trauma center between January 2015 and December 2022. Fifty-eight patients were included who underwent reamed intramedullary exchange nailing as a single-step procedure for surgical revision of posttraumatic diaphyseal femoral nonunion without any indications of infection in medical history and without clinical signs of local infection. Clinical details of the patients were analyzed and functional and radiologic long-term outcomes were determined. Results: In all patients, with and without proof of bacteria osseous, healing could be observed. The physical component summary of the SF-12 demonstrated significantly better results at least one year after the final surgical revision in case of a negative bacterial culture during exchange nailing. Conclusions: Clinical long-term outcomes demonstrated a trend towards better results following femoral shaft nonunion revision if there was no evidence for the presence of low-grade infected nonunion. In this case, a single-stage surgical procedure may be recommended.

Influence of different CCD angles on osseointegration and radiological changes after total hip arthroplasty of a triple wedge shape cementless femoral stem: a prospective cohort study.

PURPOSE: The purpose of this study was to evaluate the osseointegration and radiological outcomes in patients after total hip arthroplasty, hypothesizing different load patterns with one cementless stem design and different CCD angles (CLS Spotorno femoral stem 125° vs 135°). METHODS: All cases of degenerative hip osteoarthritis fulfilling strict inclusion criteria were treated with cementless hip arthroplasty between 2008 and 2017. Ninety-two out of one hundred six cases were clinically and radiologically examined three and 12 months after implantation. Two groups with each 46 patients were rendered prospectively and compared in clinical (Harris Hip Score) and radiological outcome. RESULTS: At final follow-up, no significant difference regarding Harris Hip Score was detected between the two groups (mean 99.2 ± 3.7 vs. 99.3 ± 2.5; p = 0.73). Cortical hypertrophy was found in none of the patients. Stress shielding was seen in a total of 52 hips (n = 27 vs. n = 25; 57% of the 92 hips). No significant difference regarding stress shielding was detected when comparing both groups (p = 0.67). Significant bone density loss was detected in Gruen zone one and two in the 125° group. The 135° group showed significant radiolucency in Gruen zone seven. No overall radiological loosening or subsidence of the femoral component was observed. CONCLUSION: According to our results, the use of a femoral component with a 125° CCD angle versus a 135° CCD did not result in a different osseointegration and load transfer with a clinically relevant significance.

Impact of keel saw blade design and thickness on the incidence of tibial plateau fracture and tibial implant-loosening in cementless medial UKR.

BACKGROUND: Tibial plateau fractures and tibial implant- loosening are severe complications in cementless unicompartmental knee replacement (UKR). The tibial keel preparation is particularly demanding and different saw blades can be used. It was hypothesized that different blade designs and thickness have an influence on the frequency of tibial plateau fractures and implant-loosening in cementless medial UKR. METHODS: 1258 patients with cementless medial UKR were included in this retrospective study between 2013 and 2020. The tibial keel cut was performed either with a double keel saw blade (DKS; 2.8 mm) and added hand guided pick or a mono reciprocating saw blade (RKB) of different thickness (2.5 mm; 2.65 mm; 2.75 mm). Tibial plateau fracture and loosening were demonstrated by standard two-plane radiographs. Tibial implant-loosening was defined as complete radiolucency and implant migration. Fracture and loosening were combined with pain and loss of function. RESULTS: In 126 patients (10%) the tibial keel was prepared with DKS, in 407 patients (32.4%) with RKB 2.5 mm, in 330 patients (26.2%) with RKB 2.65 mm and in 395 patients (31.4%) with 2.75 mm. In 4 patients (3.17%) with DKS tibial plateau fracture occurred, in 4 patients (0.99%) with 2.5 mm RKB, in 3 patients (0.92%) with 2.65 mm RKB and in 1 patient (0.25%) with 2.75 mm RKB. Significantly fewer fractures occurred with a RKB design (p = 0.007). A negative correlation between fracture incidence and RKB saw blade thickness was found (Spearman-r = - 0.93). No difference for tibial implant-loosening was shown (p = 0.51). CONCLUSION: Different blade designs and thickness have a significant influence on the incidence of tibial plateau fractures and aseptic tibial implant-loosening. The incidence of tibial plateau fractures in cementless medial UKR can be reduced by changing the design and thickness of the tibial keel saw blade. Greater thickness of RKB leads to significantly fewer tibial plateau fractures while the incidence of implant-loosening is not increasing. TRIAL REGISTRATION: This study was retrospectively registered and ethical approval was waived by the local ethical committee (No. 2020-1174).

Patients with complex proximal tibial fractures overestimate the prognosis of their injury.

PURPOSE: To investigate, if patients with complex proximal tibial fracture have realistic expectations on open reduction and internal fixation. METHODS: 114 patients (mean 49 years, SD ± 13) with closed AO-type B and C proximal tibial fracture were grouped (group B, respectively C). Prior to surgery expectations concerning knee function, pain, return to work/sports, and the risk for osteoarthritis was assessed with the Hospital for Special Surgery-Knee Surgery Expectations Survey (HFSS-KSE) and a non-validated ten-item survey. RESULTS: 92% of patients expected at least an almost natural knee postoperatively. All items regarding restoring knee function were ranked to be at least important in both groups. 65% in group B and 47% in group C expected at most occasional pain. 83% in group B and 67% in group C expected full return to work without any limitations. Patients with low physical work intensity expected significantly shorter incapacity to work in both groups (7.8, respectively 8.9 weeks). 71% in group B and 60% in group C expected to return to sports with at most small limitations. 33% in group B and 22% in group C assumed risk for osteoarthritis will be prevented by surgery. CONCLUSION: Expectations on surgery for complex proximal tibial fracture are high regardless of fracture type. The prognosis of many health and lifestyle domains was overestimated. The risk for osteoarthritis was underestimated. This study should sensitize surgeons to discuss realistic expectations. This may help to improve patient comprehension what leads to sensible expectations, resulting in improved patients´ satisfaction. LEVEL OF EVIDENCE: IV. TRIAL REGISTRATION NUMBER: 14104, Date of registration: 06/2015.

The role of low-grade infection in the pathogenesis of apparently aseptic tibial shaft nonunion.

PURPOSE: Aim of this study was to determine the rate of low-grade infection in patients with primarily as aseptic categorized tibial shaft nonunion and lack of clinical signs of infection. METHODS: In a retrospective study between 2006 and 2013, all patients who underwent revision surgery for treatment of tibial shaft nonunion without clinical evidence of infection were assessed. Bacterial cultures harvested during nonunion revision, C-reactive protein (CRP) and/or white blood cell (WBC) values at hospital admission, outcome, and epidemiological data were analyzed. RESULTS: In 88 patients with tibial shaft nonunion without any clinical signs of infection, bacterial samples remained negative in 51 patients. In 37 patients, microbiological diagnostic studies after long-term culturing demonstrated positive bacterial cultures whereas after short-term culturing for 2 days only 17 positive cultures were observed. In 12 cases a mixed culture with 2.3 different bacteria on average was detected. Among patients with negative bacterial cultures bone healing was achieved after 13.2 months. Nonunion with positive bacterial cultures required 19 (range 2-42) months until osseous healing (p = 0.009). Furthermore, nonunion with positive bacterial cultures require statistically more surgical revisions to achieve healing (2.9 ± 0.5 vs. 1.3 ± 0.1 additional procedure; (p = 0.003). Hematological studies carried out before surgical intervention did not demonstrate significant differences in CRP values (negative vs. positive cultures: 0.3 (range 0.3-2.8) mg/dl vs. 0.5 (range 0.3-5.7) mg/dl (p = 0.181) and in WBC values (negative vs. positive cultures: 7.4 (range 3.5-11.9) /nl vs. 7.3 (range 3.7-11.1) /nl (p = 0.723). Limitations of this study may include the varying amount of the at least four samples for microbiological diagnostics as well as the circumstance that for diagnosing low-grade infection swabs and tissue samples were included in this evaluation as being equivalent. CONCLUSION: The pathogenesis of nonunion may originate from low-grade infection even in patients without clinical signs of infection. In addition, nonunion with positive bacterial cultures require statistically more surgical revisions to achieve healing. Therefore, during any revision surgery, multiple bacterial samples are intended to be harvested for long-term culturing. Particularly, in tibial shaft nonunion following Gustilo-Anderson type III open fractures, low-grade infection should be suspected. TRIAL REGISTRATION NUMBER: DRKS00014657. DATE OF REGISTRATION: 04/26/2018 retrospectively registered.

Implantation Accuracy of a Lateral Unicompartmental Knee Arthroplasty: A Hoffa´s Fat Pad-Preserving Medial Approach Versus the Transpatellar Lateral Approach.

BACKGROUND: A small proportion of patients suffer from isolated lateral osteoarthritis where the sole lateral unicompartmental knee arthroplasty (UKA) is a possible treatment option. There, both a medial and a lateral surgical approach can be considered. This study should answer the question whether the lateral approach is superior to a modified medial approach in terms of implantation accuracy and subjective outcome. METHODS: In this retrospective study, 175 patients with lateral UKA were included between 2015 and 2020. In 82 patients, the lateral approach was used, and in 93 patients, the medial approach was used. To assess implantation accuracy, different imaging criteria on postoperative radiographs were analyzed. Postoperative patient-related outcome measurements (PROMs) (OKS, LEFS, and EQ5D) were evaluated. Statistical significance was assumed for P < .05. RESULTS: The tibial implant relation to the tibial plateau diameter in the lateral approach was significantly larger than in the medial approach (23.6% vs 22.2%; P < .001). Significantly more deviations >15° regarding flexion position of the femoral implant (P = .002) and a higher number of deviations of the slope was found (P = .06) in the lateral approach. The lateral approach showed a significantly higher rate of lateral positioning of the femoral component (P = .007). Post-PROMs showed significant improvement in both approaches. CONCLUSION: The lateral approach is not superior regarding different radiological accuracy criteria. The Hoffa´s fat pad-preserving medial approach showed good results in implantation accuracy and therefore is a good alternative to implant lateral UKA. In addition, significant improvement in PROMs could be demonstrated.