Bone Health

This link provides the documents and evidence used in the appraisal of health technologies used by the National Institute of Clinical Excellence for Hip prosthesis in the United Kingdom.

Incidence of sciatic &/or femoral palsies after THR ranges from 1-3%;
- incidence of nerve palsy is 1-2% of primary total hip replacement, 3-4% after revision, and 5-6% in THR for congenitally dislocated hips;
Wheeless' Textbook of Orthopaedics

Primary hip replacement requires careful patient selection, a knowledge of available prostheses, thorough pre-operative planning, familiarity with surgical exposures and sufficient manual dexterity to carry out the procedure. The aim of hip replacement is to restore the biomechanics of the diseased joint as closely as is practical. Failure to observe these principals results in premature failure of the joint replacement
G. Bannister BUPA Glen Hospital, Redland Hill, Durdham Down, Bristol, BS6 6UT Surg J R Coll Surg Edinb Irel., 1 December 2003, 332-341

Intraoperative frozen section (FS) consultation is used in evaluating possible infection in cases of hip and knee revision arthroplasty, serving as an adjunct to preoperative and intraoperative studies. We examined our experience for more than 11 years to determine if FS examination had value when sections were sent unselectively. As currently used, FS analysis has excellent specificity and negative predictive value but poor sensitivity and positive predictive value. We suggest that FS examination be used more selectively in conjunction with other studies, namely erythrocyte sedimentation rate and C-reactive protein.
William A. Kanner, MD; Khaled J. Saleh, MD, MSc, FRSC(C); Henry F. Frierson, Jr, MD Am J Clin Pathol. 2008;130(3):363-368.

Notes on -
- evaluation of the painful THR
- indications for revision:
- evaluation for loosening:
Examination
Pre-op planning
Surgical Technique
Wheeless' Textbook of Orthopaedics

REFERENCE: Wuh, H. C. K., Jones, L. C., and Hungerford, D. S., "Strain Analysis of the Proximal Femur After Total Hip Replacement," Quantitative Characterization and Performance of Porous Implants for Hard Tissue Applications, ASTM STP 953, J. E. Lemons, Ed., American Society for Testing and Materials, Philadelphia, 1987, pp. 249—263.
Strain analysis of human cadaver femora after cemented total hip arthroplasty (THA) has demonstrated a reduction in stress transfer along the proximal femur. The principal objective of this study was to determine the effect of the cementless application of a press-fit, porous-coated prosthesis on the strain experienced by the proximal femur. Using the photoelastic coating technique (PECT), five human cadaver specimens were subjected to strain analysis before and after cementless arthroplasty with a PCA total hip prosthesis. After total hip replacement, the strain magnitudes were reduced for all points along the medial border when the femur was subjected to loading conditions. A reduction of the level of strain ex�perienced by the calcar ranged from 34.7 to 43.7% under loads ranging from 750 to 2000 N— a considerably smaller reduction than that reported by previous investigators. The region of the greater trochanter was the only area of the lateral surface to demonstrate an increase in strain magnitude after THA; the other, more distal points laterally experienced a reduced level of strain. Increases in strain magnitude, although not statistically significant, were detected along the anterior aspect of the femora. Significant decreases in strain were observed at the two more distal points posteriorly, with no significant change proximally. As this investigation is an evaluation only of the immediate effect of the design of the prosthesis in achieving a press fit, and the specimens are without the benefit of bony ingrowth, additional studies are necessary to determine the effect of biologic ingrowth on the distribution of strain within the proximal femur.

Links to Annual reports in Swedish from 1997 and in English from 2002. Also copies of documents distributed at recent AAOS meetings.

This is the home of the Joint Replacement Unit (JRU) - the prosthetic team at Sahlgrenska University Hospital. One of our responsibilities is the maintenance and development of the Swedish National Hip Arthroplasty Register. Responsible for the content on this site is Professor Johan Kärrholm, MD, PhD, Göran Garellick, MD, PhD and Professor Emeritus Peter Herberts, MD, PhD.

- Link to the natural history of DDH:
- acetabular rim syndrome: - results from dysplastic hip, which stresses the labrum, resulting in labral degeneration;
- hip arthroscopy and debridement in these patients may provide the patient w/ a few additional years before total hip arthroplasty is required;
Wheeless' Textbook of Orthopaedics

Notes on approx 50 topics relating to THA.
Wheeless' Textbook of Orthopaedics

Total Hip Replacement (CBM 94-5) Bibliography of articles printed 1991-1994

Links to notes on:
- Cemented Femoral Component: Loosening:
- Bending Cantilever
- Calcar Pivot: (distal toggle)
- Medial Midstem Pivot
- Pistoning:
- Exam: for THR Loosening:
Wheeless' Textbook of Orthopaedics

Urinary Excretion Levels of Metal Ions in Patients Undergoing Total Hip Replacement with a Porous-Coated Prosthesis: Preliminary Results
In: Quantitative Characterization and Performance of Porous Implants for Hard Tissue Applications, ASTM STP 953 J. E. Lemons, Ed., American Society for Testing and Materials, Philadelphia, 1987, pp. 151—162.
by Lynne C. Jones, David S. Hungerford, Robert V. Kenna, Guy Braem, and Virginia Grant
Porous-coated prostheses implanted without bone cement are currently being evaluated for use in patients undergoing total joint replacement (TJR). One parameter under study is the potential release of metal ions from these prostheses. In order to determine if there is a systemic increase in cobalt, chromium, or nickel levels within the body subsequent to total joint replacement with a porous-coated prosthesis, 24-h urine specimens were collected from patients prior to and subsequent to TJR with a PCA total hip prosthesis. Metal ion analysis was achieved using flameless atomic absorption spectroscopy. Increases in urinary cobalt and nickel excretion were detected in several patients at six months and in most patients at one year after surgery. However, these differences were not statistically significant. No differences between the preoperative and postoperative time periods (one week, six months, and twelve months) were detected for urinary levels of chromium. Although the metal ion levels for all of the patients studied appear to be in the range handled by the body’s systemic compensatory mechanisms, which adjust levels of trace elements, continued follow-up is needed to determine the patterns and the long-term significance of metal ion release.