As the mean age of the population increases1 and the

Bulletin of the Hospital for Joint Diseases 2014;72(2):167-72 167 Anterior Knee Symptoms after S-ROM Hinge Implantation David J. Deehan, M.D., M.Sc., F.R.C.S.(Tr. & Orth.), Rajkumar Gangadharan, M.R.C.S., Ajay Malviya, F.R.C.S.(Tr. & Orth.), Alasdair Sutherland, M.D., F.R.C.S.(Tr. & Orth.), and James P. Holland, F.R.C.S.(Tr. & Orth.) Abstract Purpose: To evaluate the performance of a canal filling hinge device for complex knee arthroplasty. Methods: Thirty-seven (4 primary hinge implantation and 33 revision cases) patients who had undergone arthroplasty with the S-ROM third generation hinge device for a combination of massive bone loss or ligamentous insufficiency were prospectively examined with a minimum of 5-year follow-up. Median age at surgery was 72 years (range: 43 to 87 years). Principal indications included aseptic loosening or massive osteolysis (24 cases), infection (8 cases) and periprosthetic fracture (4 cases). All patients exhibited either grade 2 (N = 12) or grade 3 (N = 25) AORI bone loss or a grade 3 medial ligament deficiency. Results: One patient experienced implant failure (71 months), and one patient suffered late deep infection (36 months). Mean WOMAC score improved from 27 to 62. Four patients required patellar resurfacing for persistent pain. The 5-year survivorship was 86%. Conclusions: While the S-ROM device may offer satisfactory medium term outcome for complex end stage knee disease, we report a high rate of debilitating anterior knee symptoms. David J. Deehan, M.D., M.Sc., F.R.C.S.(Tr. & Orth.), Rajkumar Gangadharan, M.R.C.S., and James P. Holland, F.R.C.S.(Tr. & Orth.), are at the Freeman Hospital, High Heaton, Newcastle upon Tyne, United Kingdom. Ajay Malviya, F.R.C.S.(Tr. & Orth.), is at the Wansbeck Hospital, Woodhorn Lane, Ashington, United Kingdom. Alasdair Sutherland, M.D., F.R.C.S.(Tr. & Orth.), is at the Deakin University, Geelong, Victoria, Australia. Correspondence: David J. Deehan, M.D., M.Sc., F.R.C.S.(Tr. & Orth.), Freeman Hospital, Freeman Road, High Heaton, Newcastle upon Tyne, NE7 7DN, United Kingdom; deehan1@hotmail.co.uk. As the mean age of the population increases1 and the number of primary knee replacements increases concurrently, 2 the revision burden will logically follow suit. This trend is already witnessed in several registries and more worryingly appears to be following an exponential pattern. 3 The arthroplasty surgeon of the future is likely to perform more complex revision surgery in patients who have undergone a significantly greater number of procedures. 4 As such, the importance of understanding the performance of current revision technology cannot be understated. Such a system should be reserved for end stage disease where salvage surgery represents an alternative to fusion or excision arthroplasty. It should equally allow the surgeon to safely address the confounding variables of major bone loss and ligamentous deficiency. 5-10 Previously, the use of hinge devices has been met with poor medium term outcome, limited functional improvement. 11,12 Historically, cemented stem fixation has been reserved for the end stage knee and did find favor for the low-demand, elderly osteopenic patient. However, such fixed single axis all-cemented devices were found to transfer unacceptable stresses to the bone-construct interface with inevitable early failure. 13 Newer metaphyseal filling uncemented narrow stemmed mobile devices appear to offer the promise of improved survivorship with better function. 14,15 Our hypothesis was that a modern third generation hinge device would be met with sustained survivorship and functional improvement for these most severe revision cases. Due diligence was given to modes of failure and limitations of outcome so as to better define the role of such a device. Patients and Methods The demographic and preoperative information of this patient cohort is given in Table 1. All patients underwent conversion to an S-ROM Noiles (DePuy Inc., Warsaw, Indiana) rotating hinge system during the interval 2002 and Deehan DJ, Gangadharan R, Malviya A, Sutherland A, Holland JP. Anterior knee symptoms after S-ROM hinge implantation. Bull Hosp Jt Dis. 2014;72(2):167-72.

168 Bulletin of the Hospital for Joint Diseases 2014;72(2):167-72 Table 1 Indications and the Bone Defects According to the Anderson Orthopaedic Research Institute Classification 17 of 25 Patients Treated with SROM -Noiles Rotating Hinge Knee Replacement Demographic and Preoperative parameters No. of Patients Male:Female ratio 3:2 (23/14) Right/Left 20 / 17 Indications Aseptic Loosening Infection Periprosthetic fracture Complex proximal tibial fracture Preoperative bone loss AORI type III AORI type II Index procedure First Revision Second Revision Three or More Revisions Deformities Fixed Flexion (> 10 ) + Fixed Valgus (> 10 ) Fixed flexion (> 10 ) + Fixed Varus (>1 0 ) Correctable alignment Uncontrolled hyperextension recurvatum 2009 at the Freeman Hospital. All surgeries were performed by the senior investigators (DJD and JPH). This work was designated as an inservice evaluation and exempt from formal ethical approval by the Research & Development Unit, Newcastle upon Tyne NHS Foundation Trust and approved for anonymised publication. All patients were followed up prospectively and data corroborated through 24 8 4 1 24 13 8 19 6 8 6 23 11 Table 2 The Types of Knee Implants Explanted and Revised with S-ROM Noiles Brand of Knee Explanted Biomet - AGC * 3 Genesis 1 Insall-Burstein 1 Kinemax 9 Kinemax plus 1 Kinemax super-stabilizer 1 Nexgen LCCK 1 Porous Coated Anatomic 4 PFC 4 Stryker rotating hinge 1 TC3 2 Others (not known) 5 Not applicable (primary) 1 Number of Knee Replacements *Biomet Inc., Warsaw, Indiana; Smith & Nephew, Inc.,Memphis, Tennessee; Zimmer Corporation, Warsaw Indiana; Stryker Corporation, Warsaw, Indiana; Howmedica, Inc., Warsaw, Indiana; Depuy Orthopaedics, Inc., Warsaw, Indiana. routine clinic interview and regular interrogation of medical records. The Anderson Orthopaedic Research Institute classification 16 was employed in preoperative radiographic evaluation (Fig. 1). All patients completed preoperative and at final review WOMAC and SF36v2 scores. 17-19 There were 37 procedures performed. In four cases, a primary Noiles implant was used. The remaining 33 cases represented a revision procedure with a median of 3 (range: 1 to 7) previous procedures having been carried out prior to the index studied procedure. In eight cases, a two stage procedure was A B Figure 1 Preoperative radiographs of primary total knee replacement presenting with painful instability, 12 years after implantation.

Bulletin of the Hospital for Joint Diseases 2014;72(2):167-72 169 Table 3 Complications Following Revision Knee Replacement Using SROM Noiles Rotating Hinge Knee in 37 Patients Major Complications Number Deep infection 1 Implant failure (greater than 63 months) 1 Anterior knee pain requiring revision 2 Wound dehiscence 1 Limb lengthening (contralateral shoe-raise) 1 greater than 2 cm Patellar tendon preoperative avulsion direct 1 repair and augmentation with hamstring graft Figure 2 Postoperative 5-year follow-up radiographs of the case shown above showing the S-ROM Noiles Rotating Hinge Prosthesis in situ. performed for revision. No patient underwent a single stage revision for infection. The implants removed at surgery are given in Table 2. A representative radiograph of the revision is given in Figure 2. Surgical Procedure All procedures were carried out using a medial parapatellar approach. All sterile cases received preoperative intravenous cefuroxime, but this was withheld until after biopsy samples had been taken in infected cases. Median tourniquet time was 75 minutes (range: 55 to 95). The patellar tendon was secured using a smooth pin prior to any attempt to evert the patella, thereby reducing the likelihood of patellar tendon avulsion. One patient required tibial tubercle osteotomy. He was referred to our unit having had a cement spacer in situ for 14 months as treatment for deep infection, and there was extensive local soft tissue contraction. Specimens were obtained for routine microbiological culture, and the implants were removed sequentially using Moreland extraction kit. Manual reaming of femoral and tibial canals under direct vision with x-ray control ensured safety and provided a pressfit cementless fixation with fluted stems in the diaphyses. Metaphyseal defects were filled, using at least 50% of the proximal tibial circumference, with an uncemented porous coated sleeve ensuring maximal longitudinal and rotational stability. A tibial sleeve was used in all cases. The sleeve was attached to the stem by press fit Morse taper lock. In all cases, the tibial canal was reamed, and a stem (length 100 mm) with at least 2 mm smaller maximal diameter was used to minimize cortical impingement and thereby function solely as a centralizer. No patient underwent primary or revision patellar resurfacing at index surgery. No patient required bone grafting on either the femoral or tibial sides. The majority (N = 36) of the tibial baseplates were small or extra small. On the femoral side, again all stems were 100 mm in length of varying diameters, but in keeping with the tibial side, the femoral components were small or extra small. No large components were used on either the tibial or femoral sides. In contrast to the tibial side, femoral sleeves were only required for endosteal additional support in 12 (32%) of cases. Restoration of the joint line was often difficult due to the substantial tibial bone loss and inability to consistently locate the femoral epicondyle markers. After trial implantation a combination of stable patellar tracking through full range of movement without subluxation or impingement in conjunction with identification of residual meniscal scar tissue was used to confirm satisfactory joint line restitution. A total of seven major complications were recorded and are outlined in Table 3. All patients were followed up at 6 weeks, 3 months, and at 6 months by the senior surgeon and at 1 year and yearly thereafter by specialist nurse practitioners. The SF36 and WOMAC scores were obtained at annually after the index procedure. Implant survivorship was calculated using Kaplan-Meier Analysis using SPSSv15. Implant failure or removal of implant or was defined as an event. Results Survivorship Four patients had resurfacing of the patella subsequently for persistent anterior knee pain. These patients had undergone revision surgery with patellar resurfacing under the care of the senior investigator. In all four, there was alleviation of crepitus with almost immediate effect after secondary resurfacing. However, one of these patients had persistent anterior knee pain, which was unchanged after the secondary resurfacing. Twenty-five patients underwent aseptic revision with conversion to a hinge device. Of these, 12 had previously undergone patellar resurfacing and in only 7 of these was the patellar component considered amenable to revision (i.e., unstable or worn but with sufficient bone stock

170 Bulletin of the Hospital for Joint Diseases 2014;72(2):167-72 to allow for stable cemented patellar resurfacing). None of these patients reported significant anterior knee pain during the review period. Patellar bone grafting was not performed in any patient. The overall tibiofemoral component survivorship with 95% confidence intervals is given in Figure 3. Functional Outcome The median length of follow-up was 74 months (range: 62 to 112 months). WOMAC and SF-36v2 scores are depicted in Table 2. Six patients had extensor lag of 5, and the mean range of flexion was 105 (range: 75 to 120 ). The 5-year survival (all causes revision) of the implant was 86%, with one case of implant failure at 63 months after surgery. Radiographic assessment At final review all x-rays were assessed for evidence of gross lysis, component failure, or migration. This was not detected in any of the cases. In particular, there was no evidence of macroscopic radiolucency adjacent to the femoral or tibial sleeves. Revision One patient with a body mass index of 32.5 had implant failure at 63 months following the index procedure, which was a third revision, failing at the sleeve-stem junction of both the femoral and tibial components. This necessitated revision of implant to accommodate larger femoral and tibial sleeves and stems. This was complicated by deep infection with Morganella species, which was treated with intravenous antibiotics and explantation. Thus, the overall major complication rate in this series was 19%. Figure 3 Survivorship of the implant with 95% confidence intervals. Discussion A casual perusal of national registry data confirms the impression that the number of revision knee arthroplasty procedures is increasingly annually. With this trend comes an increase in the number of previous revision procedures found at end stage or salvage surgery. 4 The surgeon is frequently expected to resolve concomitant major bone loss in association with gross ligamentous deficiency. Traditionally, such severe laxity patterns have been addressed surgically through soft tissue repair in the acute uniaxial setting or with increased component constraint. Major bone loss requires for autologous bone grafting, which is reserved for contained defects or reliance upon metaphyseal filling components. 20,21 In this study of 37 cases with a minimum of 5-year followup, we have evaluated the clinical performance of one such modular device. In the presence of such catastrophic knee failure, this system has offered reliable improvement in knee function with excellent survivorship in the medium term. However, we have found poor anterior knee function and would recommend routine patellar resurfacing for this device irrespective of previous patellar surgery. The limitations of this work include the heterogeneous nature of the clinical case mix. There was no control group, and randomization was not possible due to the clinical complexity and by definition end stage of the disease process. In many instances, the decision to use a hinge was only taken preoperatively after careful flexion-extension gap balancing with persistent uncontrolled collateral ligament laxity. The findings from this work may not necessarily be translated to other units, and there is a need for outcome assessment from further case series or from registry linked data and follow-up. Equally, this study is unable to comment upon the longer term outcome of this device, and since only one case has been revised beyond 5 years to date (for infection), the surgical experience of such is minimal. The current instrumentation is outdated and may be upgraded, and in many instances, the senior investigator performed the majority of the procedure without recourse to perceived poorly conforming and often bulky cutting jigs. Newer instrumentation is required which matches preoperative templating and makes sense of advanced radiographic templating. Previous work on the use of hinge knee devices has painted a rather disappointing picture of the outcome. 11-13 Complication rates have ranged from 12% to 30%. The majority of follow-up has been short, thereby limiting true interpretation for the younger patient group. 10,14,22,23 Only one study had a mean follow-up of 5 or more years. 23 This is often the minimum review period for primary arthroplasty publication, and this should be seen as the equivalent benchmark for revision systems. In keeping with our work, the mean age of the patient populations studied have all been greater than 60 years and contained predominantly male patients. Such heterogeneous cases, therefore, limit comparison between implants. However, despite these methodological limitations, a variety of investigators have found clinical success with both cemented and uncemented hinge systems. 10,24-26 The common theme has been the use of such devices for either massive bone loss or MCL disruption. Our work offers a perspective on hinge knee systems through a longer follow-up and uniquely has reported a trend for persistent anterior knee pain. Our complication

Bulletin of the Hospital for Joint Diseases 2014;72(2):167-72 171 Table 4 Functional Outcome: WOMAC and SF36v2 scores of 20 Patients at Final Follow-up Following SROM Noiles Rotating Hinge Knee Replacement Preoperative Score Final Review Score WOMAC Pain 32 (13) 66 (15)* Stiffness 44 (9) 53 (8) Physical Function 25 (12) 65 (16)* SF36v2 Physical Component 29 (10) 38 (7) Mental Component 39 (8) 46 (7) Scores provided as median with 95% confidence interval; * p < 0.05 for Mann Whitney U test comparison. rate compared favorably to previous reports, although we accept that the issue of routine patellar resurfacing has been hinted at by previous experts. 12,13,25 Historically, end stage disease with major bone loss was addressed through the use of cemented stems. While such systems were met with reasonable results, the difficulty of further revision and early radiographic loosening were considered as cause of concern. Fehring and coworkers 26 recommended caution with cementless metaphyseal engaging stems. We consider the functional outcome (Table 4) and the overall complication rates are comparable to other series. We had one case of implant failure requiring revision and deep infection in the same patient following multiple revision surgeries. The majority of the component sizes used was small or extra small; only four patients required medium size components. No patient required sizes bigger than medium in both femoral and tibial components. The offset options for the tibial tray are limited to the mediolateral plane i.e., standard, right-medial/left-lateral (RM/LL) or right-lateral/ left-medial (RL/LM). Therefore, the position of the tibial tray is determined by both the metaphyseal sleeve, which centers on the tibial stem, and three options in the mediolateral plane. Thus the position of tibial tray serves only to pair up to the rotating platform polyethylene, conforming to the size of the femoral component. The weightbearing stresses are fully borne by the metaphyseal bone through the sleeve encouraging bone remodelling and preventing stress shielding in the proximal tibia and early radiographic loosening observed with diaphyseal fixation using cemented stems. Familiarity and understanding of the limitations of this device are considered critical to the maximization of outcome from this device. Joshi and colleagues 25 in a very large series of cemented components did report excellent or good results in 82% of 78 patients who underwent Endo- Model Rotational Knee prosthesis in selective patients with aseptic loosening while excluding those cases with infection. The limitation of the use of cement and requirement for constrained defects was reflected in the requirement for a structural bone grafts in three patients. They detected no theoretical problems associated with cemented stem fixation, such as severe osteopenia or periprosthetic fracture. On the contrary, Guenoun and associates 11 used a similar cemented device (Endo-Modell, Link, Wright Medical Technology, Arlington) in 85 patients and have found higher complication rates and have suggested selective use when the use of less constraining implants is impossible. They favor its use in an elderly patient with low functional demand and less comorbidities. Similar recommendations are suggested by Pour and coworkers 12 due to high complication rates of modern-generation Kinematic rotational hinge prosthesis or the Finn rotating hinge, used in 43 patients with a mean of two interim procedures. They were followed up for an average of 4.2 years and evaluated by KS score and SF-36 score. They report seven revisions caused by aseptic loosening, deep infection, or periprosthetic fracture, using another hinged prosthesis in all, resulting in five-year survival rate of 68.2%. In summary, we found this system to have key advantages. However, there was an unexpectedly high incidence of anterior knee pain. We remain cautious about the longer term outcome and complexity of further revision; therefore, longitudinal surveillance is ongoing. Disclosure Statement None of the authors have a financial or proprietary interest in the subject matter or materials discussed, including, but not limited to, employment, consultancies, stock ownership, honoraria, and paid expert testimony. References 1. Office for National Statistics. Available at: www.statistics. gov.uk/cci/nugget.asp?id=6. 2. National Joint Registry. Available at www.njrcentre.org.uk/ njrcentre/healthcareproviders/accessingthedata/statsonline/ tabid/117/default.aspx. 3. National Joint Registry for England and Wales 7th Annual Report: 2010. Available at www.njrcentre.org.uk/njrcentre/ LinkClick.aspx?fileticket=QkPI7kk6B2E%3d&tabid=86&m id=523. 4. Kurtz S, Ong K, Lau E, et al. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007 Apr;89(4):780-5. 5. Lombardi AV Jr, Berend KR. The role of implant constraint in revision TKA: striking the balance. Orthopedics. 2006;29(9):847-9. 6. Radnay CS, Scuderi GR. Management of bone loss: augments, cones, offset stems. Clin Orthop Relat Res. 2006 May;446:83-92. 7. Lucey SD, Scuderi GR, Kelly MA, Insall JN. A practical approach to dealing with bone loss in revision total knee arthroplasty. Orthopedics. 2000 Oct;23(10):1036-41. 8. Callaghan JJ, O Rourke MR, Liu SS. The role of implant constraint in revision total knee arthroplasty: not too little,

172 Bulletin of the Hospital for Joint Diseases 2014;72(2):167-72 not too much. J Arthroplasty. 2005 Jun;20 (4 Suppl 2):41-3. 9. Sculco TP. The role of constraint in total knee arthroplasty. J Arthroplasty. 2006 Jun;21(4 Suppl 1):54-6. 10. Barrack RL. Evolution of Rotating Hinge for Complex Total Knee Arthroplasty. Clin Orthop Relat Res. 2001 Nov;(392):292-9. 11. Guenoun B, Latargez L, Freslon M, et al. Complications following rotating hinge Endo-Modell (Link) knee arthroplasty. Orthop Traumatol Surg Res. 2009 Nov;95(7):529-36. 12. Pour AE, Parvizi J, Slenker N, et al. Rotating Hinged Total Knee Replacement: Use with Caution. J Bone Joint Surg Am. 2007 Aug;89(8):1735-41. 13. Inglis AE, Walker PS. Revision of failed knee replacements using fixed-axis hinges. J Bone Joint Surg Br. 1991 Sep;73(5):757-61. 14. Barrack RL, Lyons TR, Ingraham RQ, Johnson JC. The use of a modular rotating hinge component in salvage revision total knee arthroplasty. J Arthroplasty. 2000 Oct;15(7):858-66. 15. Naudie DD, Rorabeck CH. Managing instability in total knee arthroplasty with constrained and linked implants. Instr Course Lect. 2004;53:207-15. 16. Engh GA, Ammeen DJ. Classification and preoperative radiographic evaluation:knee. Orthop Clin North Am. 1998 Apr;29(2):205-17. 17. Theiler R, Spielberger J, Bischoff HA, et al. Clinical evaluation of the WOMAC 3.0 OA Index in numeric rating scale format using a computerized touch screen version. Osteoarthritis Cartilage 2002 Jun;10(6):479-81. 18. Bellamy N, Buchanan WW, Goldsmith CH, et al. Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. J Rheumatol. 1988 Dec;15(12):1833-40. 19. Ware JE Jr. SF-36 health survey update. Spine (Phila Pa 1976). 2000 Dec 15;25(24):3130-9. 20. Jones RE, Barrack RL, Skedros J. Modular, mobile-bearing hinge total knee arthroplasty. Clin Orthop Relat Res. 2001 Nov;(392):306-14. 21. Jones RE, Skedros JG, Chan AJ, et al. Total knee arthroplasty using the S-ROM mobile-bearing hinge prosthesis. J Arthroplasty. 2001 Apr;16(3):279-87. 22. Whittaker JP, Dharmarajan R, Toms AD. The management of bone loss in revision total knee replacement. J Bone Joint Surg Br. 2008 Aug;90(8):981-7. 23. Westrich GH, Mollano AV, Sculco TP, et al. Rotating hinge total knee arthroplasty in severely affected knees. Clin Orthop Relat Res. 2000 Oct;(379):195-208. 24. Deehan DJ, Murray J, Birdsall PD, et al. The role of the Rotating Hinge Prosthesis in the Salvage Arthroplasty Setting. J Arthroplasty. 2008 Aug;23(5):683-8. 25. Joshi N, Navarro-Quilis A. Is there a place for rotating-hinge arthroplasty in knee revision surgery for aseptic loosening? J Arthroplasty. 2008 Dec;23(8):1204-11. 26. Fehring TK, Odum S, Olekson C, et al. Stem fixation in revision total knee arthroplasty: a comparative analysis. Clin Orthop Relat Res. 2003 Nov;(416):217-24.