Densitometric evaluation of bone remodelling around Trabecular Metal Primary stem: a 24-month follow-up.
BACKGROUND
Today, an increasing number of total hip arthroplasty (THA) procedures are being performed. Osseointegration is a physiological phenomenon that leads to the direct anchorage of an implant by the formation of bony tissue around the implant without the growth of fibrous tissue at the bone-implant interface. Several factors may affect this phenomenon: some of these depend on the patient and others may depend on implant design and materials. Variations in periprosthetic bone mineral density (BMD) can be studied through several scans by dual energy X-ray absorptiometry (DEXA) around the femoral stem.


OBJECTIVE
The purpose of this study is to investigate correlations between periprosthetic BMD and the factors affecting osseointegration.


METHODS
We retrospectively analysed patients who underwent primary THA. In all the patients, Trabecular Metal Primary (TMP), a standard uncemented tapered stem with a proximal porous tantalum coating, was implanted. Preoperatively, postoperatively, 3 and 6 months, 1 year and 2 years after implantation, DEXA scans were performed around the femoral stem. The patients were matched for diagnosis, sex, BMD of the lumbar spine and contralateral femur, Body Mass Index and age.


RESULTS
One hundred and eight patients (51 males and 57 females) with a mean age of 73 years were studied. Different BMD changing patterns were observed and a greater bone resorption was noted in all the conditions associated with poor bone quality.


CONCLUSIONS
The proximal coating of Trabecular Metal Primary (TMP) seemed to be effective in promoting new bone formation in the proximal femur also in the conditions associated with poor bone quality.


CONCLUSIONS
At the present time, DEXA is considered the most reliable tool for evaluating bone remodelling after THA.
Department of Orthopaedics and Traumatology, University of Rome Tor Vergata, "Policlinico Tor Vergata" Foundation, Rome, Italy. elenagasbarra@tiscali.it.
Elena
E
Gasbarra
Department of Orthopaedics and Traumatology, University of Rome Tor Vergata, "Policlinico Tor Vergata" Foundation, Rome, Italy.
Riccardo
R
Iundusi
Department of Orthopaedics and Traumatology, University of Rome Tor Vergata, "Policlinico Tor Vergata" Foundation, Rome, Italy.
Fabio Luigi
FL
Perrone
Department of Orthopaedics and Traumatology, University of Rome Tor Vergata, "Policlinico Tor Vergata" Foundation, Rome, Italy.
Luca
L
Saturnino
Department of Orthopaedics and Traumatology, University of Rome Tor Vergata, "Policlinico Tor Vergata" Foundation, Rome, Italy.
Umberto
U
Tarantino
D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000379:methods; D015519:Bone Density; D016723:Bone Remodeling / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging; D006622:Hip Prosthesis / Q000592:standards*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology*; D017063:Outcome Assessment, Health Care; D011184:Postoperative Period; D011446:Prospective Studies; D012189:Retrospective Studies; D013635:Tantalum / Q000627:therapeutic use*
D013635:Tantalum
DEXA; Osseointegration; Porous tantalum; THA