Cadera/Hip/Hüfte/Hanche: Vástagos cortos con mucho cuidado

Short Bone-Conserving Stems in Cementless Hip Arthroplasty
Harpal S. Khanuja, Samik Banerjee, Deepak Jain,  Robert Pivec,  Michael A. Mont
J Bone Joint Surg Am, 2014 Oct 15; 96(20):1742-1752

Abstract

➤ Short bone-conserving femoral stems in total hip arthroplasty were designed to preserve proximal bone stock.
➤ Given the distinct fixation principles and location of loading among these bone-conserving stems, a classification system is essential to compare clinical outcomes.
➤ Due to the low quality of currently available evidence, only a weak recommendation can be provided for clinical usage of certain stem designs, while some other designs cannot be recommended at this time.
➤ A high prevalence of stem malalignment, incorrect sizing, subsidence, and intraoperative fractures has been reported in a subset of these short stem designs.
➤ Stronger evidence, including prospective multicenter randomized trials comparing standard stems with these newer designs, is necessary before widespread use can be recommended.

Cadera/Hip/Hüfte/Hanche: Cerámica contra polietileno: ¿combinación aceptable?

The case for ceramic-on-polyethylene as the preferred bearing for a young adult hip replacement

David J.W. Cash, Vikas Khanduja

Hip Int 2014; 24(5): 421 - 427

Article Type: REVIEW

Abstract

The optimum choice of bearing surfaces in total hip arthroplasty, particularly in the younger and more active patient, remains controversial. Despite several studies demonstrating good long-term results for the metal-on-polyethylene articulation, there has been a recent vogue towards the utilisation of hard-on-hard bearings for younger patients due, in part, to concerns regarding polyethylene induced osteolysis. However, well-documented complications concerning metal-on-metal bearings and the risk of fracture in ceramic-on-ceramic bearings have raised concerns regarding the principle of the hard-on-hard bearing in the active patient. With recent technological advancements in the manufacture of both polyethylene and alumina ceramics, the in vitro properties of each material with regards to strength and toughness have been significantly improved. In addition, ceramic femoral heads have consistently been shown to produce less in vivo polyethylene wear than similar sized metal heads. This paper aims to critically review the biomechanical, in vivo and clinical studies related to the use of the ceramic on polyethylene bearing, and highlights its potential use as the preferred bearing for a young adult hip replacement.

Cadera/Hip/Hüfte: Debilidad y dolor tras PTC, piensa en el nervio

Ipsilateral Inflammatory Neuropathy After Hip Surgery

Ruple S. Laughlin, P. James B. Dyck, James C. Watson, Robert J. Spinner, Kimberly K. Amrami, J. Sierra, Robert T. Trousdale, Nathan P. Staff

Mayo Clinic Proceedings

Volume 89, Issue 4, Pages 454–461, April 2014

Abstract

Objective

To identify whether new ipsilateral weakness after hip surgery may be due to an inflammatory as opposed to a mechanical process.

Patients and Methods

Seven patients (8 hip surgeries) seen between July 1, 2008, and June 30, 2011, developed unexplained ipsilateral leg weakness and pain within 1 month of hip surgery, mimicking mechanical etiologies. Cutaneous sensory nerve biopsy distant from the site of surgery was performed on all the patients. Patient medical records were reviewed for the clinical, electrophysiologic, radiologic, and pathologic features of the new neuropathy.

Results

Results of all the nerve biopsies were abnormal, showing axonal damage (7 patients), inflammation (7 patients), signs of ischemic injury (7 patients), and nerve microvasculitis (6 patients). Six patients were treated with intravenous methylprednisolone. At median follow-up of 6 months, 6 patients showed improvement in function and pain.

Conclusion

In this case series, we demonstrate that inflammatory neuropathy is an important etiologic consideration in some patients with ipsilateral weakness and pain after hip surgery. In these patients, the inflammatory mechanism was ischemic injury due to microvasculitis. Identification of these patients through clinical suspicion and subsequent nerve biopsy may lead to improved outcomes with prompt initiation of immunotherapy.

General: alendronato en la necrosis atraumatica de cabeza femoral.

The use of alendronate to prevent early collapse of the femoral head in patients with nontraumatic osteonecrosis. A randomized clinical study.

Lai KA1, Shen WJ, Yang CY, Shao CJ, Hsu JT, Lin RM.

J Bone Joint Surg Am. 2005 Oct;87(10):2155-9.

Abstract

BACKGROUND:

Osteonecrosis of the femoral head is the most common diagnosis leading to total hip arthroplasty in young adults. Joint-preserving treatment options have been mainly surgical, with inconsistent results. Alendronate (a bisphosphonate agent) has been shown to lower the prevalence of vertebral compression fractures and could potentially retard the collapse of an osteonecrotic femoral head. The purpose of this study was to test the effect of alendronate in preventing early collapse of the femoral head in patients with nontraumatic osteonecrosis.

METHODS:

Forty patients with Steinberg stage-II or III nontraumatic osteonecrosis of the femoral head and a necrotic area of >30% (class C) were randomly divided into alendronate and control groups of twenty patients each. Patients in the alendronate group took 70 mg of alendronate orally per week for twenty-five weeks, while the patients in the control group did not receive this medication or a placebo. The patients were observed for a minimum of twenty-four months. Harris hip scores, plain radiographs, and magnetic resonance imaging scans were obtained.

RESULTS:

During the study period, only two of twenty-nine femoral heads in the alendronate group collapsed, whereas nineteen of twenty-five femoral heads in the control group collapsed (p < 0.001). One hip in the alendronate group underwent total hip arthroplasty, whereas sixteen hips in the control group underwent total hip arthroplasty (p < 0.001).

CONCLUSIONS:

Alendronate appeared to prevent early collapse of the femoral head in the hips with Steinberg stage-II or IIIC nontraumatic osteonecrosis. A longer duration of follow-up is needed to confirm whether alendronate prevents or only retards collapse.

LEVEL OF EVIDENCE:

Therapeutic Level I.