538 - Minimally Invasive Spine Surgery its Rationale, Benefits and Effects o...

#538 Minimally Invasive Spine Surgery its Rationale, Benefits and Effects on Patient Outcomes a Comparison of the Classic Open Approach versus the Muscle Sparring approach

MIS Techniques and Outcomes

Poster Presented by: D.W. Kucharzyk


D.W. Kucharzyk (1)
E. McCorkle (2)
D. Budimir (3)

(1) The Orthopaedic, Pediatric & Spine Institute, Crown Point, IN, United States
(2) Integrated Spine, Valparaiso, IN, United States
(3) Precision Spine Inc, Downers Grove, IL, United States


Minimally Invasive spine surgery for instrumented lumbar fusions is an attractive concept with advantages for the surgeon and the patient but question arises does it efect patient outcomes and how does it compare to the classic open approach. For it to be accepted it should have similar outcomes to the classic open approach in terms of fusion rates and recovery but to exceed the classic open approach it needs to effect outcomes of the patients in terms of a shorter hospitalization, less blood loss, less muscle damage,rapid entry into physical therapy, quicker return to work and improvement in outcome measurement.

The impetus for minimally invasive or morseo a minimally disruptive approach centers on the need to minimize paraspinal muscle damage seen with the classic open approach. the open approach with the inherent stripping of the paraspinal muscles does lead to increased blood loss, loss of muscle functionality, increasd postoperative pain and even chronic pain syndromes. The minimally disruptive minimally invasive approach has shown less paraspinal muscle damage as seen the the works of Sihvonen, Kawaguchi, Styl, Gejo, Kim and Stevens. This has lead to quicker retun to functional activities and sooner return to work.

A study was undertaken to compare MIS surgery involving a percutaneous muscle splitting approach and a minimally invasive muscle sparring minimally disruptive approach to the clasic open posterior fusion. 200 cases were involved with 100 cases in the open group(OG) compared to the MIS group(100 cases) that were randomized into a MIS I percutaneous muscle splitting approach(50) and a MIS II muscle sparring minimally disruptive approach(50) with follow up to two years. All were sinlge level instrumented fusions with interbody fusions with similar implants and bone grafting materials. The only varaible was the approach. All were evlauated for blood loss, duration of surgery, duration of hospitalization, narcotic use, fusion rates, rehabiltiation and return to work status, Outcomes were measured using the ODI, SF-36,BPS, and FCE.


OG: OR time110min, blood loss300ml, hospitalization3.3days, narcotic use51hrs, fusion rate92.8%

MIS I: OR time125min, blood loss100ml, hospitalization2days, narcotic use25hrs, fusion rate93.3%

MIS II: OR time90min, blood loss75ml, hospitalization1.5days, narcotic use12hrs, fusion rate94.5%

Outcomes measurements:

ODI: open 52.5preop 28.4postop MIS I 53.9preop 19.2postop MIS II 54.1preop 12.2postop

SF-36: open 27.6preop 39.7postop MIS I 21.7preop 48.6postop MIS II 27.1preop 49.6postop

BPS: open 16.4preop 8.1postop MIS I 15.9preop 5.1postop MIS II 17.1preop 2.0postop

Return to Work: measured via FCE and job descriptions

one month: open 15% MIS I 30% MIS II 60%

three months: open 30% MIS I 60% MIS II 80%

six months: open 55% MIS I 80% MIS II 90%

Conclusion: MIS surgery offers advantages for the properly selected patient ofering shorter hospitalization, less blood loss, less narcotic use, quicker entry into physical therapy which equated to a sooner return to work. Most importantly, MIS has shown improvements in all outcomes measurement data when compared to the classic open approach and when further separated by MIS approach the muscle sparring minimally disruptive approach performed better than the percutaneous access approach and when compardd to the open approach the outcomes were even more dramatic. But the final conclusion and most important for the surgeon is that the fusion rates were similar in all three groups.