2013 Highlights “Balancing the Hype”: Total Hip Arthroplasty

2013 Highlights “Balancing the Hype”: Total Hip Arthroplasty

Papers from 2013 American Academy of Orthopedic Surgeons (AAOS)

Surgical Approach

“Is there faster Recovery after Direct Anterior Approach (DAA) than Posterior Approach Total Hip Arthroplasty”

Deshmukh M.D. et al

Conclusion: “Functional recovery was faster in patients with DAA on the basis of TUG and M- FIM scores up to 2 wks. No differences were observed between groups at 6 wks, 12 wks, and one year. Complications of DAA included one fracture and 4 pts with groin pain due to psoas tendon impingement. In PA groups, one patient had a dislocation and 2 had groin pain.”

“Similar Improvement in Gait Parameters with Direct Anterior and Posterior Approach Total Hip Arthroplasty”

Orishimo MS and Kremenic M.D. et al

Conclusion: “THA performed via DAA and PA offer similar improvement in gait parameters up to one year follow up with the exception of internal/ external ROM.”

“Which Muscle Sparing Approach is Better- Direct Anterior or Antero-lateral in total hip Arthroplasty?”

Iwaki M.D. et al

“No significant difference with respect to strength up to 3 wks… or in clinical scores.”

Conclusion; We found no differences between DAA and MIS-AL approach clinically except for cup anteversion which is more accurate in the DAA group compared to the MIS-AL group.

“Differences in Hip Strength Recovery with Direct Anterior and Posterior Approach Total Hip Arthroplasty”

Rathop M.D. et al

Conclusion: “Both DAA and PA THA offer similar recovery in hip muscle strength up to one year with the exceptions of persistent ER strength deficit in PA group, and flexion strength deficit in the DAA group at 6 wks. This may be related to the release of the external rotators in PA group and hip flexor irritation in the DAA groups.”

Symposium : The Anterior Approach Is the Answer: AGAINST

Haddad, BSc, MCh, FRCS, FFSEM; London

Excerpts:

“The perceived benefits are minimal soft tissue damage, avoidance of the abductors, optimal visualization of the acetabulum, and preservation of the posterior capsul and external rotators. There is however very little evidence that it reduces dislocation.”

“Pellici et al described an “enhanced posterior repair” which drastically reduces the number of dislocations following THR through a posterior approach.

The authors found their dislocations fell from 4% to 0% in one study of 395 cases, and from 6.2% to 0.8% in 124 cases.”

“This enhanced repair is described by Suh et al. The dislocation rate without repair was 6.4% in 250 primary THR’s, but was maintained at 1% in 96 augmented with the posterior repair.” Clin Orthop Relat Res 2004; 162

Siguier et al reviewed 1037 primary THR’s carried out through a minimally invasive anterior approach and reported a dislocation rate of 0.96% “The anterior approach has a learning curve and is found difficult by many, and hence may sacrifice component orientation and soft tissue balance if undertaken inexpertly.”

A specialized fracture table is often required and intra operative XR fluoroscopy, due to more difficult access to the femur…”fractures may occur” and “must be performed carefully”.

“The anterior approach is considered a difficult procedure to adopt when compared to posterior or trans gluteal exposures.” Spaans et al described their learning curve through their first 46 cases. They found the operative times nearly doubled, increased blood loss and greater complication rates…” Even as they gained experience their results did not improve significantly. Masonis et al demonstrated the use of fluoroscopy and operative time was shown to have a learning curve in the first 100 cases.

Lateral Cutaneous Femoral Nerve injury (LFCN) is at risk from the retraction of the tissue required. Patients may complain of “parasthesias” in the lateral thigh or a burning pain or dysesthesia. Bhargava et al found in his series of 81 THR’s,..the incidence of LFCN neuropraxia was 14.8 %. Conclusion: The disadvantages of the anterior approach are its labor intensiveness, learning curve, a specialized operating table and intra-operative fluoroscopy.

“Further analysis is required so that we can understand the risk-benefit ratio of the anterior approach. At present the evidence that this is the answer to the dislocation risk that we run for every THR is lacking. The Anterior Approach should stay in the hands of enthusiasts while we continue to optimize existing approaches to improve patient outcomes.”

All surgical approaches have advantages and disadvantages. To suggest the Direct Anterior Approach has dramatic and definitive superiority as the current “marketeers” would imply, is not accurate.

Hip Resurfacing

Symposium : Update on Metal Bearing Issues: Hip Resurfacing- I still do it but with caution

Vail M.D.

Excerpts:

“Surface Replacement is technically demanding, with results and risks which are significantly impacted by procedural details such as implant position and the structural integrity of the femoral neck. Femoral neck fracture is the most common early complication after hip resurfacing. Revision due to loosening, unexplained pain, and adverse effects of metal ions are increased in persons of smaller stature and female patients… durability of the femoral component fixation is predicated upon the metal-cement-bone interface…developmental dysplasia and osteonecrosis have been reported to have increased risks of early failure…”

“Adverse metal ion reactions have been reported in local tissue after metal on metal Hip Resurfacing. It is not possible to conclusively predict ahead of the procedure which patients might be more susceptible to an adverse reaction at this time.”

Recommendations:
  • Avoid patients with known sensitivity to metal
  • Assess bone quality
  • Template the radiographs to assess the potential to restore hip joint mechanics
  • Patients with severe CAM deformity will be at risk due to inability to restore femoral head offset
  • Results with hip dysplasia and osteonecrosis in general ,are not as good as in osteoarthritis
  • Inform patients about the risks and encourage them to follow up after the procedure in order to detect problems