Contribution of the BioballTM head-neck adapter to the restoration of femoral offset in hip revision arthroplasty with retention of a well-fixed cup and stem.

PURPOSE: Failure to restore the femoral offset of the native hip is a potential cause of dysfunctional hip arthroplasty. The aim of this study was to report our experience of using a modular head-neck adapter in revision THA, specifically analyzing its usefulness as a tool to correct a slightly diminished femoral offset. MATERIALS AND METHODS: This was a retrospective single-center study including all hip revisions performed at our institution from January 2017 to March 2022 where the BioBallTM head-neck metal adapter was used. The preoperative and one year follow-up modified Merle d'Aubigné hip score was used to evaluate functional outcomes. RESULTS: Of a total of 34 cases included for revision, the head-neck adapter system was used specifically in six patients (17.6%) to increase femoral offset, retaining both the acetabular and femoral components. In this subgroup of patients, mean offset decrease after primary THA was 6.6 mm (4.0-9.1), equivalent to a mean 16.3% femoral offset reduction. The median modified Merle d'Aubigné score went from 13.3 preoperatively to 16.2 at one year follow-up. CONCLUSION: The use of a head-neck adapter is a safe and reliable procedure that may allow the surgeon to easily correct a slightly diminished femoral offset in a dysfunctional THA without the need to revise well-fixed prosthetic components.

Can the intra-operative measurement of the diameter of the femoral head help surgeons to choose the best size of the acetabular cup?

PURPOSE: We hypothesized that the intra-operative measurement of the femoral head may increase the accuracy of the acetabular cup size optimal selection in total hip arthroplasty (THA). The purpose of this clinical research was to analyze the correlation between the estimated cup size from intra-operative measurement of the femoral head and the pre-operative templated cup size. METHODS: A prospective observational single-center study was conducted from June 2019 to January 2020 including primary THA (n = 100). All cases were pre-operatively templated. The measurement of the anterior-posterior diameter of the femoral head was routinely intra-operatively performed. Any definitive implanted cup was considered as "oversized" when the size was > 4 mm than the diameter of the native head. RESULTS: The median (interquartile range) size of the implanted cup, pre-operative planned cup size, and diameter of the femoral head were measured 52 (50-54) mm, 50 (48-54) mm and 49 (45-51) mm, respectively. Pre-operative planned size cup accurately predicted the implanted cup or differed in only one size (2 mm) in 77 (78%) cases. Otherwise, intra-operative femoral head measurement method accurately predicted the implanted or differed in only one size (2 mm) in 51 (87%) cases (p = 0.097). CONCLUSION: The intra-operative femoral head measurement is a simple and reliable tool to help the surgeons choose the best size of the acetabular cup and is as reliable as the pre-operative templating in order to avoid cup oversizing in THA. Utmost caution is warranted whenever the cup reamer is > 4 mm than the anterior-posterior diameter of the native head.

Outcomes of hip arthroplasty with concomitant hardware removal: influence of the type of implant retrieved and impact of positive intraoperative cultures.

INTRODUCTION: The impact of residual internal fixation devices on subsequent procedures about the hip has not been clearly well defined. The objective of the current study is to evaluate the outcome of hip arthroplasty after hardware retrieval as a one-stage replacement, to analyze possible differences related to the type of removed implant, and to assess the impact of unexpected intraoperative cultures during implant retrieval. MATERIALS AND METHODS: We present a retrospective study including all those cases undergoing hip arthroplasty with concomitant hardware removal (cannulated screws, intramedullary nail, or dynamic hip screw) from 2005 to 2018. We evaluated demographics, intraoperative cultures, early infection rate, and other complications. RESULTS: A total of 55 cases were included in the study. The median time between the implant surgery and the hip arthroplasty was 113 days. The removed devices included 6 cannulated screws, 34 intramedullary nails, and 15 dynamic hip screws. Up to 74.5% of the failed osteosynthesis belonged to intertrochanteric femoral fractures. Dislocation rate was 9.1% (1.8% requiring revision surgery), 25.5% of the cases needed further new surgeries after the hip arthroplasty, and 49.1% died during the follow-up period. Any-cause revision surgery and mortality rates were significantly increased after intramedullary nail removal. Intraoperative cultures were performed in 46 cases, and in 9 (16.4%), there was bacterial contamination: 6 cases (10.9%) presented one single positive culture and 3 (5.5%) presented ≥ 2 positive cultures for the same microorganism. A total of five cases (9.1%) presented early prosthetic joint infection that required debridement. None of these five cases had presented positive cultures at the implant removal. CONCLUSION: According to our results, hip arthroplasty with concomitant hardware removal is related to a high 5-year mortality rate, mainly when intramedullary nail is retrieved. Whereas a high risk of early prosthetic joint infection is associated, it seems not to be related to the elevated presence of unexpected positive cultures.

Removal of protruding screws in a painful total hip arthroplasty: A case report.

Persistent pain after total hip arthroplasty can be challenging for the orthopedic surgeon. We present a case of a 56-year-old female with an uncommon cause of persistent pain after total hip replacement, due to protruding screws with the subsequent impingement of surrounding soft tissues. The patient presented persistent groin pain after total hip revision surgery. After ruling out infection and loosening, an infiltration of iliopsoas muscle was performed, with only temporary improvement. The magnetic resonance depicted the conflict of the screws with the surrounding soft tissues, in close relation to the iliopsoas muscle, the external obturator muscle and the sciatic nerve. Revision surgery was performed, removing the screws, and implanting a new liner with complete remission of symptoms. Our case presents an atypical cause of pain due to surrounding tissue lesions by offending screws with complete resolution after only screw removal. In the clinical study of persistent pain following a total hip replacement, screws length, and protrusion should be considered and ruled out as a possible and treatable etiology. Removal of the screws after cup integration can be a conservative and effective strategy to treat the pain.