Optimizing leg length correction in total hip arthroplasty Abstract Purpose Residual feeling of leg length discrepancy (LLD) is a common cause of patient dissatisfaction following total hip arthroplasty (THA). The purpose of this study is to propose a method for determining an optimal leg length correction goal in THA. Methods We conducted a retrospective study of 132 patients to examine the radiographic LLD (R-LLD), perceived LLD (P-LLD), and whether or not the patient has an uncomfortable feeling about the leg length after THA. Results The residual discomfort rate in all patients was 9.1% (12/132 patients), and ten of these 12 patients felt uncomfortable due to a longer leg length. When R-LLD was within 7 mm, the rate was 6.8% (8/118 patients), which is nearly equal to the rate of 7.8% (5/64 patients) in cases in which R-LLD was within 2 mm. On the other hand, when R-LLD was 8 mm or more, the rate was 57.1% (4/7 patients). Conclusions The results of our study show that 7 mm may be a reasonable threshold for reducing the residual discomfort. However, even with little or no R-LLD, some patients will continue to experience discomfort. We think that this is because of pre-operative differences between R-LLD and P-LLD in such cases. If the patient has a pelvic declination on the affected hip side and a lumbar scoliosis angle that is convex toward the affected hip side before surgery, the ideal length may be a little shorter than the radiographic isometry, since such patients are likely to feel a longer leg length than that shown radiographically.

Correction to: The optimization of the length of the lower limbs after hip arthroplasty Authors first and last names for the first and third authors have been interchanged. The correct presentation is given above.

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Long-term survivorship of a monoblock long cementless stem in revision total hip arthroplasty Abstract Purpose The purpose of this study was to assess the clinical outcomes, complications, and survival of a long cementless titanium femoral stem in revision total hip arthroplasty (THA) at a minimum five year follow-up. Methods Between 2000 and 2010, 114 patients (116 hips), with a mean age of 68 ± 12 years, underwent revision THA using a KAR® stem (DePuy, Leeds, UK). The main reasons for revision were aseptic loosening (82%), periprosthetic joint infections (PJI) (11%), and periprosthetic fractures (6%). Mean follow-up was ten ± three years (range, 5–16). Harris Hip Score (HHS), Oxford Hip Score (OHS), and Postel-Merle d’Aubigné (PMA) score were recorded. Radiographic analysis assessed stem osseointegration and subsidence. Survival was analyzed using the Kaplan-Meier (KM) method and cumulative incidence function (CIF). Results Post-operative HHS was 83 ± 15 (range, 35–99) and OHS was 37 ± 8 (range, 8–48). PMA score significantly increased from 12 ± 2 (range, 5–18) pre-operatively to 14.6 ± 2 (range, 9–18) post-operatively (p = 0.0004). The radiographic Engh score was 15 ± 8 (range, 7–22). Stem subsidence was observed in two cases (3%). At ten years, five stems had been revised, three for infections and two for periprosthetic fractures. Using the KM method, ten year survival free of stem revision for aseptic loosening was 100%, free of revision for any reason 95%, and free of any re-operation 81%. Conclusions The present study reported satisfactory outcomes and survival of a long tapered unlocked cementless femoral stem in revision THA at a minimum follow-up of five years.

Size of ischial fibro-ostosis is associated with heterotopic ossification after total hip arthroplasty Abstract Purpose The hypothesis of the present study was that degenerative fibro-ostosis (FO) of the ischial hamstring tendon insertion is a risk factor for heterotopic ossification (HO) following THA. Methods We followed 103 consecutive patients (43 males, 60 females, mean age 61 years) who underwent unilateral cementless THA for primary hip osteoarthritis and investigated the incidence of HO within the first 12 months after surgery. On pre-operative radiographs, a standardized evaluation for FO of the ischial hamstring tendon insertion concerning horizontal, vertical, and square dimensions was performed. HO was classified according to Brooker on radiographs at 12 months post-operatively. Results At follow-up, 56 patients (54%) had no radiographic evidence of HO, 23 (22%) were classified as Brooker I, 17 (17%) as II, 6 (6%) as III, and 1 (1%) as IV, respectively. Patients with post-operative HO had significantly greater vertical (3.0 mm vs. 2.3 mm, p = 0.001) and horizontal (47.9 mm vs. 39.1 mm, p = 0.025) dimensions of FO than patients without HO. Patients with FO and a vertical dimension of ≥ 2.5 mm were more likely to develop HO (55.6%) than patients with a vertical FO dimension of less than 2.5 mm (34.7%, OR = 2.35 p = 0.047). A weak correlation between the vertical and horizontal size of FO and the severity of HO was observed. Conclusion Radiographic evidence of asymptomatic FO is a potential risk factor for the development of HO following THA and may be used as a simple diagnostic tool to pre-operatively identify patients at risk for post-operative HO. This association has not been previously described and further research to confirm the present findings and to justify additional prophylactic treatment in these patients is warranted.

Lateralization in reverse shoulder arthroplasty: a descriptive analysis of different implants in current practice Abstract Introduction Since its first description, the concept of reverse shoulder arthroplasty (RSA) has evolved. The term lateralization remains unclear and is used to describe implants that lateralize on the glenoid side, the humeral side, or both. The objective of this study was to provide a clear definition of lateralization and to measure the lateralization achieved by the most commonly used implants. Materials and methods Twenty-eight different configurations with 22 different implants were analyzed. Glenoid, humeral, and global lateralization was measured on digitized templates. Implant lateralization was normalized to the lateral offset of the Delta III. Each implant was defined as a combination of one of two glenoid categories (medialized glenoid (MG), lateralized glenoid (LG), and one of four humeral categories (medialized humerus (MH), minimally lateralized humerus (LH), lateralized humerus (LH+). In addition, implants were separated in categories of 5-mm increments for global offset (medialized RSA (M-RSA), minimally lateralized RSA (ML-RSA), lateralized RSA (L-RSA), highly lateralized RSA (HL-RSA), and very highly lateralized RSA (VHL-RSA). Results The global lateral offset of the Delta III was 13.1 mm; global lateral offset of all designs in this study varied between 13.1 and 35.8 mm. Regarding their global lateral offset, five implants are M-RSA (lateral offset < 18.1 mm), five ML-RSA (18.1–23.1 mm), seven L-RSA (23.1–28.1 mm), six HL-RSA (28.1–33.1 mm), and one VHL-RSA (33.1–38.1 mm). Conclusion There is high variability in the amount of lateralization provided by the majority of RSAs currently available. This descriptive analysis can help surgeons understand the features of implants in the market based on their lateralization in order to adapt the surgical technique depending on the expected lateral offset of the design being implanted.

A case series of cementless revision total knee arthroplasty in patients with benzoyl peroxide allergy Abstract Purpose The contact allergens nickel, cobalt, and chromium are often discussed as possible triggers of allergic reactions to orthopedic implants. Additionally, acrylates and polymerization additives in bone cement (e.g., benzoyl peroxide (BPO)) have been implicated as triggers of eczema, wound healing disorders, and aseptic implant loosening. We report about six patients with aseptic loosening after total knee arthroplasty (TKA), who underwent revision surgery after testing positive for BPO hypersensitivity. Methods After clarification of possible other causes of implant failure, epicutaneous testing had been performed and the implants were replaced in a two-stage procedure with cementless, diaphyseal anchoring, hypoallergenic (TiNb-coated) revision endoprostheses. Results Epicutaneous testing revealed a BPO allergy in all six patients and an additional nickel allergy in three of the six patients. There was no histopathological or microbiological evidence for a periprosthetic infection. The clinical follow-up showed a low level of pain with good function, a stable knee joint, and proper implant position. The Knee Society Score (KSS) with its subscales Knee Score and Functional Score improved post-operatively from 43 to 70 points and from 47.5 to 68.3 points, respectively. Two implant-specific complications occurred: femoral stress shielding two years post-operatively with no further need for action and aseptic loosening of the tibial stem with the need of revision three years post-operatively. Conclusions The regression of complaints after replacement with cementless and nickel-free revision implants suggests allergic implant intolerance. Implantation of a cementless, hypoallergenic endoprosthesis might, therefore, be a surgical treatment strategy in patients with evidence of allergies.

Customized implants for acetabular Paprosky III defects may be positioned with high accuracy in revision hip arthroplasty Abstract Purpose In revision hip arthroplasty, custom-made implants are one option in patients with acetabular Paprosky III defects. Methods In a retrospective analysis, we identified 11 patients undergoing cup revision using a custom-made implant. The accuracy of the intended position of the implant was assessed on post-operative 3D CT and compared to the pre-operative 3D planning in terms of inclination, anteversion, and centre of rotation. In addition, the accuracy of post-operative plain radiographs for measuring implant position was evaluated in relation to the 3D CT standard. Results We found a mean deviation between the planned and the final position of the custom-made acetabular implant on 3D CT of 3.6° ± 2.8° for inclination and of − 1.2° ± 7.0° for anteversion, respectively. Restoration of center of rotation succeeded with an accuracy of 0.3 mm ± 3.9 mm in the mediolateral (x) direction, − 1.1 mm ± 3.8 mm in the anteroposterior (y) direction, and 0.4 mm ± 3.2 mm in the craniocaudal (z) direction. The accuracy of the post-operative plain radiographs in measuring the position of the custom-made implant in relation to 3D CT was 1.1° ± 1.7° for implant inclination, − 2.6° ± 1.3° for anteversion and 1.3 mm ± 3.5 mm in the x-direction, and − 0.9 mm ± 3.8 mm in the z-direction for centre of rotation. Conclusion Custom-made acetabular implants can be positioned with good accuracy in Paprosky III defects according to the pre-operative planning. Plain radiographs are adequate for assessing implant position in routine follow-up.

In-office shoulder arthroscopy and tenotomy of the long head of the biceps tendon—a cadaveric feasibility study Abstract Purpose Studies have shown that isolated tenotomy of the long head of the biceps (LHB) improves significantly pain scores, active range of motion and Constant score in elderly patients with massive and irreparable cuff tears with no osteoarthritis. This cadaveric study was performed to assess the feasibility of a tenotomy of the LHB and subacromial corticosteroid injection using a minimally invasive in-office setting under local anaesthesia on awake patients. Materials and methods Twenty scare-free shoulders were included in the study. We performed the procedure in an in-office setting using a wrist arthroscope with no fluid, connected to wireless camera and light source. A standard shoulder arthroscopy was finally performed in order to analyse the tenotomy quality and detect possible iatrogenic lesions. Results The LHB tendon was cut fully in all cases, the mean length of the proximal stump of the LHB was 0.4 cm (range, 0.3–0.7 mm) and the mean duration of the surgery was 3.5 minutes (range, 2.43–3.86 min). No iatrogenic lesion occurred during the in-office procedure. Conclusion This cadaveric study suggests that it is feasible and safe to perform, under local anaesthesia, a minimally invasive arthroscopic tenotomy of the LHB and subacromial injection using an in-office setting. Further clinical studies are needed to confirm the reliability, indication and effectiveness of this technique.

Proximal femoral replacement in non-oncologic patients undergoing revision total hip arthroplasty Abstract Purpose Proximal femoral replacements (PFRs) have been recently utilized in complex revision arthroplasties where proximal femoral bone is compromised. The purpose of this study is to evaluate the clinical outcomes, complications, and survivorship of PFRs as a salvage treatment for severe bone loss after non-oncologic revision total hip arthroplasty. Methods This is a retrospective review of all patients who underwent femoral revision surgery using a single design PFR between 2004 and 2013 at our institution. Forty patients (41 hips) were included with a mean age of 64 years (29–90). According to Paprosky classification, 15 femurs had type IIIB defect, and 26 had type IV defect. Patients were followed for a mean of five years (2–10). The average length of reconstruction was 150 mm (81–261). A Kaplan–Meier analysis was used to determine the survival of the PFR. Results A total of nine patients (9 PFRs, 22%) were re-operated upon. Three re-operations were for infection, two for dislocation, two for aseptic loosening, and two for periprosthetic fracture. The survivorship at five years was 95.1% for revision of the femoral stem for aseptic loosening. We did not find length of the segmental reconstruction or the indication for revision, to be a risk factor for implant failure or re-revision. Conclusions Proximal femoral replacements have shown an acceptable survivorship in non-oncologic revision hip arthroplasties for severe proximal femoral bone loss. The frequent use of constrained liners may decrease the risk of dislocation due to the loss of the abductor mechanism encountered in these complex reconstructions.