Clinical Outcome After Replacement of Distal Femur/Proximal Tibia in a Heterogeneous Patient Cohort: Function Following Tumour, Trauma, and Loosening.

BACKGROUND: Distal femur and proximal tibia replacements as limb-salvage procedures with good outcome parameters for patients with tumours have been broadly described. However, the overall midterm outcome in a mixed, heterogeneous patient collective is still unclear. PATIENTS AND METHODS: We retrospectively analysed 59 consecutive patients (33 for primary and 26 for revision surgery) between 1998 and 2017. Indication for implantation was tumour (n=16), periprosthetic fracture (n=14), traumatic fracture (n=14), infection (n=10), aseptic loosening (n=3), and pathological fracture (n=2). The mean follow-up duration was 3 years. Clinical functions were evaluated by Toronto Extremity Salvage Score and Knee Society Score. Knee extension and flexion force were measured. RESULTS: The overall survival rate of arthroplasties was 59% (n=35). Major complications were observed in 36 (61%) patients. During the follow-up period, 14 (24%) patients died. We recorded periprosthetic joint infection in 21 (36%) patients, recurrence of tumour in two (3%), and aseptic implant failure in three (5%). The mean Toronto Extremity Salvage Score was 66±33, and the mean Knee Society Score was 49±30. The mean extension force on the operated side was significantly reduced at 60° and 180° compared to the healthy side (p=0.0151 and p=0.0411, respectively). CONCLUSION: Distal femur and proximal tibia replacements showed limited clinical function in a heterogeneous patient collective. Indication for implantation should be considered carefully.

Preoperative femoral abduction angle correlates with initial postoperative lateral hip pain after transcutaneous osseointegrated prosthetic system (TOPS) in transfemoral amputees.

PURPOSE: To analyse whether a preoperative femoral abduction angle (FAA) correlates with postoperative initial lateral hip pain (LHP) in above-knee amputees (AKA) treated with transcutaneous osseointegrated prosthetic system (TOPS). METHODS: Pre- and postoperative long-leg radiographs of eighteen unilateral AKA (mean age 51.55y ± 12.16) were retrospectively measured. FAA was measured on both sides. Pain intensity of LHP was measured by numeric rating scale (NRS) preoperatively and every week for four weeks from the first day of weight loading. Pearson's r was calculated for correlation. Furthermore, odds ratio for LHP ≥ 5/10 NRS and relative FAA > 13° was calculated. RESULTS: FAA significantly decreased in the postoperative period (pre/post. 15.33° ± 4.22; p < 0.001). Median LHP was 0/10 NRS (min.0, max.3) preoperatively and 4/10 NRS (min.2, max. 7, p < 0.001) postoperatively after first loading. Interestingly, it decreased within four weeks to a median of 0.5/10 NRS (min.0, max. 3) without intervention. A strong correlation was seen on the amputated side between preoperative FAA and LHP after loading (r = 0.835, p < 0.001), as well as the relative FAA to LHP after loading (r = 0.732, p < 0.001) and between the gap of pre- to postoperative FAA and LHP. Odds ratio for LHP ≥ 5/10 and relative FAA > 13° was 6.4 (95%CI = 0.55; 74.89). CONCLUSION: The preoperative FAA strongly correlates with postoperative LHP. Surgeons should be aware of high risk of LHP that can limit prosthetic training. High preoperative FAAs should be realised in the decision meeting of TOPS implantation and pre-rehabilitative reduction of the FAA should be taken into consideration.

Reduction of Patella-baja and Pseudo-patella-baja Does Not Improve Range of Motion in Patients After Mega-TKA.

BACKGROUND/AIM: Patella baja (PB) and pseudo-patella baja (PPB) have been shown to negatively influence outcomes after total knee arthroplasty. We hypothesized that there is a high incidence of PB and PPB after megaprosthetic total knee arthroplasty (M-TKA), and that this is associated with reduced range of motion. PATIENTS AND METHODS: We retrospectively analysed all patients in our Orthopaedic Trauma Department after distal femur or proximal tibia replacement. Preoperative and one-year postoperative follow-up included measurement of range of motion and detection of PB and PPB using radiological indices. RESULTS: We included 44 patients (age: 73±19 years). Preoperative PB detected by ISI could be reduced from 13 (36%) to 11 (25%) (p<0.01). Preoperative vs. postoperative ISI was 0.88±0.23 vs. 1.06±0.45 (p=0.03). PPB was observed preoperatively in 23 (63%) patients vs. 24 (54%) postoperatively. Preoperative vs. postoperative CDI was 0.70±0.24 vs. 0.95±0.43 (p=0.002). Preoperative flexion was 91°±30° vs. 85°±24° postoperatively (p>0.05). CONCLUSION: Both PB and PPB are frequently observed after M-TKA. A reduction in PB and PPB alone does not improve postoperative range of motion.