1	Techniques in Minimally Invasive Hip Surgery: MIS 2 Incision Approach Paul J Duwelius, M.D. Adjuvant Assoc. Prof. OHSU Clinical Attending St. Vincent Hospital Portland, Or.
2	What is minimally invasive hip surgery and why would you do it?
3	Minimally Invasive Total Hip Surgery Advantages Smaller incision utilized Decreased hospital stay Shorter recovery time Much faster physical therapy More stability because of less soft tissue dissection
4	It’s not about the size of the incision!
5	Why I Became Interested in MIS Orthopaedic arthroplasty patients are the only remaining inpatients Desire to improve the total hip critical pathway Realized the two incision approach was possible from cadaver studies Combination of the two incisions was very familiar because of my trauma background
6	Traditional THR Excellent long term results with porous implants (Anatomic Stem ) Berger et. al. JBJS 2001 Portland results: publication pending
7	Anatomic 10 year results J.B.V. Butler, M.D., John Hayhurst, M.D., & Paul J. Duwelius, M.D. Portland, Oregon USA
8
9	Complications:
10	Revisions
11	“Default prosthesis”
12	“Mini” Incision THA 87 Consecutive Cases VerSys® Hip System 74 Proximally Coated Stem 7 Fully Coated Stem 6 Cemented Stem Trilogy® Acetabular System Posterolateral Approach Incision Length: 3-4 Inches
13	“Mini” Incision THA Primary Diagnosis
14	“Mini” Incision THA Demographics
15	“Mini” Incision THA Average OR Time: 83 Minutes Average Length of Stay 2.57 Days
16	“Mini” Incision THA Harris Hip Scores
17	“Mini” Incision THA Complications: 1 Fracture Calcar Cerclage Wires Placed – Resolved 1 Hematoma Irrigation and Debridement - Resolved
18
19
20
21
22
23
24	MIS Total Hip Surgical Development Cadaveric studies over a 10 year period by Dana Mears & Investigational Centers Surgical Technique evolving @ the clinical sites Surgical instruments developed by Zimmer to facilitate surgery First surgical cases done by Drs’ Berger, Duwelius, Tanzer, & Hartzband @ MIS sites Several newer instruments and ultimately implants will evolve for the MIS technique
25
26	MIS Surgical Technique: Anterior Approach Anterior incision: 4-5cm. Through the first incision with modified instruments the femoral head & neck are removed The Trilogy cup & liner are inserted after special modified reamers have prepared the acetabulum
27
28	MIS Surgical Technique: Posterior Approach Posterior incision: 2-3cm. Preparation of femoral canal: reaming,broaching & stem insertion Versys Fiber Metal Midcoat Prosthesis utilized initially Versys Beaded Fullcoat is the stem of choice: Procedure is stem dependent
29
30
31
32
33	Portland MIS Data 65 consecutive MIS procedures 25 Proximally Coated 40 Fully Coated IRB protocol completed Trend toward decreased hospital stay Minimal postoperative hip precautions Majority of patients released within 24 hours ( 7 patients released 2^nd day )
34	MIS HIP Primary Diagnosis
35	MIS HIP Demographics
36	MIS HIP OR Times
37	MIS HIP Length of Stay St Vincent’s Hospital Portland, Oregon
38	MIS HIP Harris Hip Scores
39	Complications Case 6: Recurrent dislocation 4 days and 9 days postop Closed reduction/hip brace; resolved Case 15: Subsidence/loosening Revision @ 3 weeks Case 18: Deep hematogenous infection related to lung abcess Device removal
40	Complications Case 33: Dislocation at 5 days Closed reduction; resolved Case 42: Intraoperative Calcar split Repaired with cerclage wires; resolved
41	MIS vs. Conventional Posterior Approach 8 patients had bilateral THR: MIS vs. Conventional posterior THR 6/8 were both done by PJD 2/8 done elsewhere 4 day stay for posterior approach 1 day stay for MIS No patient would prefer traditional hip over MIS
42
43
44
45
46
47
48
49
50
51
52
53
54
55	MIS Questions Cost savings may be significant Can surgical technique reliably be reproduced by other surgeons? Can hip surgery ultimately be done in an outpatient setting?
56	MIS Trends Patients tolerating the procedure better than the traditional procedure Hospital stay has been shorter than our 4 day average stay with conventional THR Recovery is quicker: PT same day Hip precautions are virtually nil with two incision technique
57	MIS Conclusions It’s about the technique—not size of incision Better surgical interval Less Dissection Smaller incisions are good Instrument dependent: evolving Training is critical: more difficult than “mini” Surgical procedure is good, safe and reproducible in our institution with 70 cases performed Need long term F/U
58