Total Hip Arthroplasty Advancements and Functional Predictors

Mini-Open Procedures “minimally invasive” = incision <10cm long Posterolateral, Anterolateral, Anterior, and 2-Incision approaches claims: decreased tissue damage, blood loss, post-operative pain, scar length, and length of hospital stay; quicker rehabilitation, restoration of function, and return to normal lifestyle

Posterolateral incise gluteus maximus, elevate gluteus medius and minimus off capsule, incise posterior capsule leaves abductors “largely untouched” allows immediate weightbearing, slightly increased dislocation rate

Anterolateral incision through fascia lata, anterior 1/3 of gluteus medius detached from femur (new techniques spare this detachment) decreased dislocation rate, increased chance of limp due to gluteal nerve injury or failure to repair gluteus medius attachment

Anterior enters between TFL and sartorius superficially, rectus femoris and gluteus medius deeply; no muscle detachment increased operative time, fracture rate; requires special operative table

2-Incision “least invasive”, anterior incision between TFL and sartorius, posterior incision spares small external rotators critics have found only mild improvement in pain and function, higher complication rates (blood loss, malposition, operative time, repeat surgery), and increased muscle damage

Comparison of Approaches Mini vs. Standard Posterolateral Approach no significant difference in invasiveness as measured by inflammation (serum interleukin-6, C- reactive protein, and hemoglobin levels) Mini-posterior vs. 2-Incision Approach measured muscle damage (hip strength), antalgic gait (SLS time, velocity), function (changes in hip moments during walking and stair-climbing) mini-posterior approach had significantly greater improvement in hip extensor strength, SLS time, and hip flexor moment

Functional Outcomes sex (female) was found to be a statistically significant predictor of success at 6 months (ability to walk without an AD, change of 9 or more on the LEFS) age (younger), surgery type (THA vs. pin), and hip abductor strength at discharge (3+ or more) significant predictors of successful outcome at 60 days; presence of LE contracture and discharge to institution significant predictors of unsuccessful outcome at 60 days (success = independent ambulation with/without AD for 50 ft on a non-carpeted surface)

presence or absence of hip precautions following anterolateral approach made no significant difference in dislocation rate pre-operative Physical Therapy vs. none shows decreased discharge to rehab facility, earlier performance of transfers, and significant improvement in: 25m and 6-minute walk tests, cadence, stride length, and velocity at 3 weeks s/p; hip flexor, extensor, and abductor strength and ROM at 6 months s/p in Japan, no correlation between comorbidity severity and outcome was found; but in the UK, lower comorbidity severity showed statistically significant greater improvement in basic and instrumental ADLs

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