5. MEDULLOSCOPY IN PRIMARY AND REVISION HIP ARTHROPLASTY Preparation of the femoral shaft in primary total hip arthroplasty is routinely performed without direct visualization of the endomedullary canal. Bleeding from the bone surface during cemented hip arthroplasty compromises the bone-cement interface. Endoscopy of the femoral canal was used by us to evaluate this “third generation canal preparation techniques with the use of 10mm 0° laparoscope we inspected 90 femoral canals during canal preparation. Click here to see video "Primary Hip Arthroplasty With Endoscopy".
Intramedullary bleeding was standardised on a 4. scale going from a completely dry femoral canal (type A) to rapid filling of the canal with blood caused by arterial bleeding (type D). Bleeding was measured after femoral broaching, insertion of dry swabs, cleaning the canal with a hand brush, rinsing the canal using pulsed lavage (PULSAVAC, Zimmer) and suction of the canal using a canal filling tampon with suction (PREP-IM KIT, Smith & Nephew). Previously unknown finding were observed during endoscopy of the medullary canal. Severe arterial bleeding, often originating from the posterior wall was noticed in 6 cases.
This bleeding was controlled by standard laparoscopic diathermy tools. Eccentric lateral broaching of the shaft was observed in 3 cases. Endoscopy also facilitated the broaching of a very thin femoral canal in 2 dysplastic hips and in 4 uncemented femoral components. We concluded that endoscopy was an effective tool for quality control in primary cemented hip arthroplasty, also useful in broaching the difficult primary canal. We recommended the testing in vivo by endoscopy of new techniques to improve canal preparation. Cement wherein cement revision of the femoral component is occasionally used in revision hip arthroplasty provided the existing cement mantle is stable, intact and there is room for recementation of a new implant. Campbell from Australia reports on 2 cases in which a classic arthroscope is used to assist the preparation of the cement mantle for cemented revision hip arthroplasty. They describe the use of an arthroscope for the assessment of the integrity of the cement mantle, to access the removal of the previously inserted distal cement centraliser and to assist in the preparation of the cement mantle for recementation.
In their paper they describe how illumination of the medullary cavity with a disposable light source and irrigation was insufficient to visualise the distal cement centraliser and the cement mantle. A 4 mm arthroscope was used to irrigate and simultaneously visualised the cement mantle medulla. The arthroscope allowed excellent visualisation of the cement mantle and confirmed the absence of cracks or defects in the two described cases. I high speed drill was used to roughen the cement mantle and remove the corrosion and biological film from the interface. Under endoscopic control the drill was used to abrade the existing cement mantle. A new femoral component was inserted into the intact existing cement mantle that had been roughened and dried to allow interdigitation of the new cement. They recommend the use of this technique when a cement-in-cement femoral revision is indicated. Arnold Berman (ref. 3) in 1987 is to our knowledge the first orthopaedic surgeon who describes the use of an arthroscope to assist cement removal in revision hip surgery. He uses the fibre optic head lamp and the light source of an arthroscope to enhance visualisation during cement removal. 63 total hip revisions were divided into two groups comparing 21 trochanteric osteotomised revisions to 44 with trochanteric sparing techniques. In the non osteotomised group there was a 21% decreased blood loss, a 14% decrease in persistent abductant weakness and a 14% decrease in subluxation and dislocation. Furthermore there was a 30%decrease in operating time and 50% reduction in intra operative femoral perforation. In a prospective study of 25 cases we evaluated the usefulness of endoscopy in the reduction of complications during cement removal in revision hip arthroplasty. Click here to see the video "Revision Hip with Medulloscopy". Both, a 10 and a 5mm 0° laparoscope was used to perform femoral cement removal under endoscopic control. We found excellent visualisation of the cement mantel in all cases. The 10 mm laparoscope gave the best view of the medullary canal. However the large diameter of the scope made insertion of instruments for cement removal difficult. A standard 5mm laparoscope allows more room for use of instruments in the distal part of the femur. Standard chisels can be positioned in the diaphysial cement under endoscopic control.
We found ultrasound tools very useful for distal cement plug perforation, cement and fibres tissue removal were clearly visible by means of the endoscope in all cases. Neither trochanteric osteotomy nor extended proximal femoral osteotomies were used in any of these cases. However the average operating time was 3 hours an 49 minutes. Porsch introduces a miniaturized chiselling system (Swiss OrthoClast) that allows endoscopically controlled cement removal even from deep within the femur in hip revision arthroplasty. Their devise consists of a control unit, a hand piece, a set of chisels of different lengths and shapes, a set of plug extraction tools and a specially designed intrafemoral endoscope. It uses simple ballistic principles to fracture the bone cement. Inside the hand piece is a projectile accelerated that strikes the chisel head. The tip moves at high speed and with a small excursion towards the cement, which is fragmented mechanically by the movement of the chisel tip without generating heat. According to their reported devices validated in a prospective, international, multicenter study they publish on their first 28 clinical procedures. The average duration of cement removal is 32 min (13 to 75 min). In all but one case, the cement was completely removed and they only had one case of cortical fissuring. This same pneumatically-powered ballistic chisels under endoscopic control have also been reported on by Drake C. and Ezzet K (ref. 6) reports on the use of this system in 15 complex femoral revision cases where normally an extended trochanteric osteotomy was anticipated. 14 cases had well fixed distal cement and 1 case was a well fixed cementless component. In all 15 cases (100%), the femoral component was successfully revised without a trochanteric osteotomy. 3 cases required a small single femoral window less than 1 cm. In total 80 % of the cases that would ordinarily require an osteotomy were successfully managed without an osteotomy, window or perforation. The endoscope allowed direct visualisation within the distal femur and the pneumatic chisels were small enough to fit alongside the endoscope inside the femur. Only one case report so far describes arthroscopic assisted revision of the acetabular component in total hip arthroplasty. In the case report by Lavernia (ref. 19) he describes how an arthroscopic shaver was used to remove osteolytic lesions proximal to the acetabular cup during revision hip arthroplasty. Excellent debridement was obtained and cortical bone allograph was used to fill the void areas behind. This is the only report that describes successful endoscopic treatment of pelvic osteolytic debridement with the use of an arthroscopic shaver.
6. OTHER APPLICATIONS OF BONE ENDOSCOPY Intraosseus endoscopic examination of the femoral neck and head was performed during the course of percutaneous screw fixation in 12 patients with slipped capital femoral epiphysis (SCFE). They report on 13 patients. In every case the authors were able to distinguish between trabecular bone and the physeal cartilage using an endoscope. There was obvious articular penetration in 2 patients which was documented using an endoscope. In one patient with pain and chondrolyses, chronic joint penetration was observed endoscopically at the time of the revision operation. In another patient they observed 20 pin-penetrations during cannulated screw fixation of a severe slipped capital femoral epiphysis. Lu reports on arthroscopically assisted replacement of a dynamic hip screw. They report on a dynamic hip screw penetrating into the hip joint. They report on a case with unrecognized joint penetration of the lag screw. This was replaced by a shorter lag screw with arthroscopic assistance through a new portal of the screw canal. Other authors described intramedullary application of an endoscope for fracture reduction (Bojkow), autogenic bone grafting (Kim) and treatment of osteomyelitis (Herle). In one clinical case, after successfully testing new techniques of intramedullary bone endoscopy in vitro, Oberst highlights on salvage of a lost intramedullary reamer in the femur using special endoscopic tools. Roberts describes the use of “medulloscopy” for visualization and irrigation of sepsis of non-union of long bones. After testing different scopes in cadaveric experience, they performed a study on 2 cases of aseptic femoral non-union, 1 infected femoral non-union with chronic osteomyelitis, 2 cases of healed tibia fractures with chronic osteomyelitis and 1 aseptic non-union of the tibia and 1 case of tibial osteomyelitis secondary to IV drug abuse. Visualization of the non-union site was achieved in the majority of cases (6 out of 7) and additional diagnostic information was obtained using this medulloscopy in 86 % of the cases (6 out of 7). Vascular catheterization techniques were used by Sans to allow access to the entire marrow cavity through a minimal percutaneous approach. The developed a device to reach the epiphysis of the long bone and performed both animal and human anatomical cadaver experiments. They describe as an alternative technique when a direct approach to the leasional site in long bones in dangerous or impossible. They promote it in cases of preventive cement injections in weak end bones. In the treatment of 3 femoral head chondroblastomas a technique was used of percutaneous extraarticular curettage. They describe the technique a which the tumour cavity in the femoral head is reached through a tunnel drilled from the lateral cortex through the medullary canal of the femoral neck. A video arthroscope was used to assist visualisation during the curettage of the cartilage tumour. Bone graft material was packed into the tumour cavity without fear of subsequent leakage of this bone graft into the joint space. At an average follow up of 25 months all these femoral head tumours had healed without recurrence. There were no complications related to the approach. They promote this technique as a hip arthrotomy plus a cortical window in the femoral head or neck is avoided. They recommend this technique for the treatment of selected be 9 femoral head or neck lesions other than chondroblastomas (ref. 38). The use of hip arthroscopy to perform accurate placement for core decompression of the femoral head has been published by Rusch (ref. 32). They describe the technique whereby the patient is placed on the factory table in a supined position and the guide wire for core decompression is inserted into the middle the infarct. By doing so the surgeon is assured of accurate placement of the guide wire into the centre of the infarct. This same technique of endoscopically assisted grafting in osteonecrosis has been reported by us. Click here to view the video "Endoscopically Assisted Grafting in Osteonecrosis". We described EAGO on 12 patients. A similar surgical technique was used in all cases. An almost similar procedure was used for hips, knees and shoulder. - Harvest of autologous cancellous bone graft of the iliac crest using a 44mm acetabular reamer
- Insertion of a standard DHS treated guide wire under image intensifier control
- Drilling of a 9mm tunnel in the sick zoned
- Inspection of this canal using a 5mm laparoscope
- Aggressive debridement under endoscopic control using standard ACL 10mm and 11mm reamers and curettes
- Washout of all the necrotic fragments using pulsatile lavage
- Filling of the debrided zone with cancellous auto graft under endoscopic control.
The sharp border between healthy and necrotic bone was seen in all cases (see picture 1). Endoscopy improved the accuracy of the debridement of avascular bone. In one case of endoscopically assisted grafting of osteonecrosis of the hip, accidental perforation of the cartilage was observed using the 5mm laparoscope. This perforation went unnoticed on image intensifier control. We concluded that endoscopy is a simple and effective technique to improve the accuracy of existing techniques for core decompression and grafting in osteonecrosis. A 5mm laparoscope used in 5 cases and a 4mm arthroscope in 2 patients. 6 patients underwent medulloscopy with irrigation fluid and one patient underwent medulloscopy without irrigation. In one case visualisation was not possible at a young non-union just past the mid shaft of a femur which was beyond the reach of the length of the arthroscope. There were no instances of fluid overload, electrolyte abnormalities or compartment syndromes related to the medulloscopy procedure. They describe the successful use of medulloscopy to assess the viability of the endostium endomedullary cavity. Morgan-Jones (ref. 23) et all. Reported the successful use of arthroscopic pin tract debridement in 25 pin tracts in 6 patients. Gerber SD. and Patel D. (ref. 8) reported on the arthroscopic removal of a femoral rod in a patient with distal migration of the rod into the joint. Bojkow WP. (ref . 3) was the first to report on medulloscopy assisted fracture reduction and already in 1985 published on 350 patients using endoscopically assisted fracture repositioning. A first case of endoscopic bone grafting for delayed union of the humerus was presented by Johnson at the 13th. Annual Seminary of Arthroscopic Surgery in Phoenix-Arizona. Based on this experience, Kim SJ. (ref. 14) in Korea reported on a series of 8 endoscopic bone grafts for delayed- and non-union. A similar surgical technique which was used in all cases. Two portals were made, one to visualize and one to debride and refresh the fracture site. In every case the debridement and bone grafting was done under direct visual control. In their experience, endoscopic bone grafted resulted in an enhancement of bone union and less morbidity and increased range of motion of the adjacent joint. In contrary to the Korean series Lanny Johnson (ref. 13) also reported on, not only 4 humeral lesions but also 5 patients with tibial fractures. They describe a 3-protal technique with endoscopic resection of the fibres delayed-union. There were no intra-operative complications and no compartment syndrome. Bony union occurred in all but one patient at an average of 4 months. 7. VIDEO EQUIPMENT AND ENDOSCOPES Orthopaedic surgeons have often tried their standard arthroscopes to perform medulloscopy of the femoral canal. Our own cadaver studies show a very disappointing visualisation of the endo-medullary canal when a standard arthroscope is used. The fiberoptic light source in an arthroscope is insufficient to illuminate the intramedullary canal. The 20-30° angled lens gives a distorted view of the medulla and insufficient distinction between bone and cement. Our early findings have been confirmed by the early studies on medulloscopy published by Roberts. They too tried both a 4mm arthroscope and a 5mm laparoscope. Standard arthroscopes in their evaluation of femoral non-unions were also too short to inspect the distal part of the femoral intramedullary canal. Although the use of standard knee arthroscopes is often insufficient to assist cement removal in revision hip arthroplasty, there have been some successes reported in the literature. Successful use of this standard arthroscope has been described for bone endoscopy in cannulated screw placement for treatment of slipped capital epiphysis (Barcet), pedicle screw placement (Stauber), cement within cement revision hip arthroplasty (Camble) and intramedullary treatment of septic non-unions of femur and tibia (Roberts). Roberts from the University of Louisville has been the first to introduce the term end-medulloscopy. In his tibial cadaver experiments he tested three different standard available scopes. He tested a standard knee arthroscope, hip arthroscope and a flexible rhinolaryngoscope. The standard arthroscope was only able to access 19,1% +/-1% length of the intramedullary canal of the tibia. This improves to 29,1% +/- 3,8% for the hip arthroscope. The flexible rhinolaryngoscope was able to visualise 94,1 +/- 1,8% of the tibial canal. Oberst M, Bosse A and Holz U. (ref. 23) describe the experimental use of their endoscopic system in a watery environment. As there are so far no animal experiments on the effect of high volume rinsing of the medullary canal, they do not yet recommend their intramedullary bone endoscopy technique in a watery environment. This group from Stuttgart developed a stiff endoscope with a separate working channel (8 by 9 mm). Through this working channel a separate tube can be inserted to clean both the lens and washout the intramedullary canal. With their set come extra instruments like diathermy needles and a grasping forceps. A proctoscope was used as an entriportal in the fossa piriformis in contrary to other scopes, the video camera is mounted at a 90° angle to the working channel(ref. 26). 8. SUMMARY AND DISCUSSION Intramedullary bone endoscopy with intramedullary preparation under endoscopic control is only scarcely mentioned in literature and very few papers mention local or systemic side effects (ref. 2.3.2 Govaers) To the best of our knowledge now studies so far concentrate on the wise of intramedullary pressure when a scope is inserted in vivo in bleeding bone (ref. 2.3.2 Oberst). On of the major disadvantages of endoscopic manipulation of the bone, especially of the femur, is the control of the intramedullary bleeding. Continuous irrigation of the intramedullary canal of the femur has been very unsuccessful. For endoscopy of the tibia however a tourniquet can be used at the upper leg. There is a lag in the literature on in vivo experimental studies on endoscopically assisted canal preparation in revision hip surgery. Undoubtedly more research (in animal models) should be performed to found out more about the possible systemic and local side effects of this procedure (ref. 2.3.2 Oberst). Cement removal from the femoral canal is a technically demanding procedure. Perforation of the shaft, fracture and inadequate removal of cement are well described in the literature. Successful application of endoscopy for cement removal have been described by Köster (ref. 16), Porsch (ref. 24) and Govaers (ref. 8). Although the need for trochanteric osteotomies and windows was reduced. One of the major disadvantages was the long operating time. This seems to be reduced by the use of pneumatically powered ballistic chisels. We found ultrasound cement plug perforation indispensable for endoscopically assisted cement removal. There are other disadvantages in the use of endoscopy. Not only is it time consuming, it is difficult to perform in a bowed femur, often threatened in revision hip cases. We found it to have a very steep learning curve to avoid damage to these expensive endoscopic equipments. Furthermore, spinal epidural anaesthesia, controlled hypotension were necessary to control the bleeding inside the femoral canal. Both experiments of Schmidt and Roberts show that introduction of an intramedullary scope in the tibia and of lithotripsy in the femur do not appear to cause dangerous rise in the intramedullary canal pressure (ref. 2.3.2 Swiss OrthoClast). Kim SJ. (ref. 14) highlights the risk of endoscopic bone grafting for treatment of non-union. Not only requires this technique substantial surgical skills, it may not be applicable to all cases due to local anatomy. It must be kept in mind that handling of the endoscopic instruments can jeopardise the adjacent neurovascular structures. Another potential hazard is, the risk of compartment syndrome due to fluid infusion and bone grafting in a limited space. Their bone grafting was done under a low infusion pressure and they saw no signs of increased compartment pressure. The average age of our patients was 7O years and the time between primary and revision procedure 69 months. Total blood loss was 2.5 units on average. A comparison was made of the complications between the aseptic and the septic cases. There was 13.44% risk of intra-operative complication in the aseptic cases and a much higher (38%) risk in the septic cases. The risk for perforation was however not predictable by 3 operative X-ray using the AAOS or Endo-Clinic classification. A detailed analysis was made of the residual cement after the primary procedure in septic revisions. There was statistically more cement distal to the cement plug and in the distal part of the medullary canal at Gruen zones for and 11. There was one broken instrument and three broken ultrasound tips during endoscopically assisted cement removal. 1. | Bassett GS Bone endoscopy: direct visual confirmation of cannulated screw placement in slipped capital femoral epiphysis. J Pediatr Orthop. 1993 Mar-Apr;13(2):159-63 | 2. | Beck A, Strecker W, Gebhard F, et al Influence of prosthesis design on intramedullary femoral pressure during the implantation of femoral stem prostheses. Unfallchirurg 2001;104:1140-1144. | 3. | Berman AT, Salter FL, Koenig T. Revision Total Hip Replacement without Trochanteric Osteotomy Orthopedics.1987 May;Vol.10/N°5 | 4. | Bojkow WP, Karalin AN. Bone marrow endoscopy. Orthop Travmatol Protez. 1989;3:68-69 | 5. | Campbell DG, Rietveld JA Technique for arthroscopic assisted revision hip arthroplasty. Int Orthop. 2001;25(‘):236-8 |
6. | Drake C, Ace M, Maale GE. Revision total hip arthroplasty. AORN J.2002 Sep;76(3):414-7,419-27,quiz 428,431-2 | 7. | Ezzet K. Endoscopically Assisted Total Revision Arthroplasty with pneumatically powered narrow calibre chisels. Société Internationale de Chirurgie Orthopédique (SICOT), 2001. | 8. | Gerber SD, Patel D. Arthroscopic removal of femoral intramedullary rod Orthop. Rev 1987;16:91-96 | 9. | Govaers K, Roels J, Geenen E, Maes J. Endoscopically assisted hip surgery Efort Congres. 1997 Barcelona-Spain: presentation | 10. | Govaers K. Endoscopically assisted hip surgery. Annaheim California. Feb;1999:Scientific Exhibition presented at the 6th Annual Meeting of the American Academy of Orthopaedic Surgeons. | 11. | Govaers K. Endoscopically assisted grafting in osteonecrosis. Presentation at the ARCO Meeting in London-U.K. Brit J of Bone and Joint Surg.annexe. 1997. | 12. | Hardy P, Decrette E, Jeanrot C, Colom A, Lortat-Jacob A, Benoit J. Arthroscopic treatment of bilateral humeral head osteonecrosis Arthroscopy. 2000 Apr;16(3):332-5 | 13. | Härle A. Die optisch kontrollierte Markausräumung bei der Osteomyelitis-Behandlung. Z Orthop. 1985;123:388-394. | 14. | Hillekamp et al.;Goettingen (Germany). Cement removal with ballistically powered chisel in hip revision arthroplasty. 5th Congress of the EFFORT, Rhodes (Greece), 06/2001. |
15. | Johnson LL, Morrison KM, Wood DL. The application of arthroscopic principles to bone grafting of delayed union of long bone fractures. Arthroscopy 2000;16:279-289. | 16. | Kim SJ, Shin SJ, Yang KH, et al. Endoscopic bone graft for delayed union and non-union. Yonsei Med J. 2000;41:107-111. | 17. | Klein PDM, Rahn BA, Frigg R, et al. Reaming versus non-reaming in medullary nailing: Interference with cortical circulation of the canine tibia. Arch Orthop Trauma Surg 1990;109:314-316. | 18. | Koster G, Willert H, Buchhorn GH. Endoscopy of the femoral canal in revision arthroplasty of the hip. A new method for improving the operative technique and analysis of implant failure. Arch Orthop Trauma Surg.1999;119(5-6):245-52 | 19. | Köster G, Willert HG. Die intraossäre Endoskopie: Anwendungsmöglichkeiten und erste Ergebnisse. Osteologie. 1997;6:22-29. | 20. | Köster G, Willert HG, Buchhorn GN. Endoscopy of the femoral canal in revision arthroplasty of the hip: A new method for improving the operative technique and analysis of implant failure. Arch Orthop Trauma Surg 1999;119:245-252. | 21. | Lavernia CJ, Moreyra CE, Dapuzzo MR. Arthroscopic shaver-assisted total hip arthroplasty revision. J Surg Orthop Adv.2004 Fall;13(3):174-6 | 22. | Lu KH. Arthroscopically assisted replacement of dynamic hip screw for unrecognized joint penetration of lag screw through a new portal. Arthroscopy.2004 Feb;20(2):201-5 | 23. | McCarthy J, Puri L, Barsoum W, LeeJA, Laker M, Cooke P. Articular cartilage changes in avascular necrosis: an arthroscopic evaluation. Clin Orthop. 2003 Jan;(406):64-70 | 24. | Morgan-Jones RL, Burgert S, Richardson JB. Arthroscopic debridement of external fixator pin tracts. Injury 1998;29:41-42 | 25. | Oberst M, Holz U. Intramedullary bone endoscopy (IBE) Erste klinische Anwendung einer neuen endoskopischen Technik. Unfallchirurg. 2005 Jan;108(1):75-8. | 26. | Oberst M, Bosse A, Holz U. In der Diskussion: Intramedulläre Knochenendoskopie (IBE) Erste experimentelle Ergebnisse der Endoskopie des langen Röhrenknochens Intramedullary bone endoscopy (IBE). First results of experimental intramedullary endoscopy of long bone. Der Unfallchirurg. Abstract Volume 105 Issue 9 2002;853-855 – DOI 10.1007/s00113-002-0450-3. | 27. | Porsch M, SchmidtJ. Cement removal with an endoscopically controlled ballistically driven chiselling system. A new device for cement removal and preliminary clinical results. Arch Orthop Trauma Surg. 2001 May;121(5):274-7. | 28. | Porsch M,Schmidt J. Clinical experiences with an endoscopically controlled new device for extraction of the cement plug in hip revision arthroplasty. Hip Int. 2001;11(3) | 29. | Porsch, Schmidt, Brimmers, Koeln (Germany). Risk of fat embolic syndrome in hip revision arthroplasty using a modified intrafemoral lithotripter Société Internationale de Chirurgie Orthopedique (SICOT),1999. | 30. | Porsch, Schmidt, Koeln (Germany). Intrafemoral endoscopy in hip revision arthroplasty. Société Internationale de Chirurgie Orthopedique (SICOT),2001. | 31. | Porsch, Schmidt, Koeln (Germany). Cement removal with an endoscopic controlled miniaturized ballistically driven chiselling system (Swiss OrthoClast)-clinical results. Société Internationale de Chirurgie Orthopédique (SICOT),1996 | 32. | Porsch et al.;Koeln (Germany). Clinical experiences with an endoscopically controlled new device for extraction of the cement plug in hip arthroplasty. Hip International, Vol.11,n°. | 33. | Roberts CS, Statton JO, Walker JA, Seligson D, Hempel D. Medulloscopy of the tibia: initial report of a new technique. Arthroscopy. 2000 Nov;16(8):865-8. | 34. | Roberts CS, Walker JA, Statton J, Seligson D. Medulloscopy for sepsis or non-union: Early clinical experience with the tibia and femur. Arthroscopy. 2001 Nov-Dec;17(9):E39 | 35. | Ruch DS, Satterfield W. The use of arthroscopy to document accurate position of core decompression of the hip. Arthroscopy. 1998 Sep;14(6):617-9. | 36. | Sans N, Estivalezes E, Swider P,Despeyroux ML,Loustau O,Galy D, Chiavassa H, Railhac JJ. Percutaneous catheterization of the long bones: experimental study. Eur Radiol. 2004 Sep;14(9):1698-701. Epub 2004 Feb. | 37. | Schemitsch EH, Kowalski MJ, Swiontkowski MF, et al. Cortical bone flow in reamed and unreamed locked intramedullary nailing: A fractured tibial model in sheep. J Orthop Trauma 1994;8:373-382. | 38. | Schmidt J, Porsch M, Hackenbroch MH, Koebke J, Brimmers P. Modified intracorporeal lithotripsy for cement removal in hip prosthesis exchange operations—experimental principles. Z Orthop Ihre Grenzgeb. 1998 Jan-Feb;136(1):44-9 | 39. | Stauber MH, Basset GS. Pedicle screw placement with intraosseous endoscopy. Spine.1994 Jan;19(1):57-61. | 40. | Stoica et al.;Bukarest (Rumania) Our experience in revision of the total hip replacement with Swiss OrthoClast 5th Congress of the EFFORT, Rhodes (Greece), 06/2001. | 41. | Stricker SJ. Extraarticular endoscopic excision of femoral head chondroblastoma. J Pediatr Orthop. 1995 Sep-Oct;15(5):578-81. | 42. | Suarez-Suarez MA, Murcia-Mazon A. A simple method to facilitate mini-incision in total hip arthroplasty. J Arthroplasty. 2004 Apr;19(3):395-6. | 43. | Sulk et al.;Goettingen (Germany). Explanation of non cemented loosened hip stems with ballistical powered chisel. 5th Congress of the EFFORT, Rhodes (Greece), 06/2001. | 44. | Toms AD, Leese N, Gregson PA, McGeoch C. The use of the cystoscope in revision hip arthroplasty. J Arthroplasty. 2001 Jun;16.(2001).4. | 45. | Wall EJ, Kolata R, Roy DR, Mehlman CT, Crawford AH. Endoscopic pelvic osteotomy for the treatment of hip dysplasia. J Am Acad Orthop Surg. 2001 May-June;9(3):150-6. | 46. | Wenda K, Ritter G, Degreif J, Rudigier J. Pathogenesis of pulmonary complications following intramedullary nailing osteosynthesis. Unfallchirurg 1988;91:432-435. | 47. | Wiese M, Rubenthaler F, Willburger RE, Fennes S, Haaker R. Early results of endoscopic trochanter bursectomy. Int Orthop. 2004 Aug;28(4):218-21. Epub 2004 Jun;9 | 48. | Yamamoto Y, Ide T, Ono T, Hamada Y. Usefulness of arthroscopic surgery in hip trauma cases. Arthroscopy. 2003 Mar;19(3):269-73. |
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