- Email: [email protected]
Quality of life following femoral osteotomy and total hip arthroplasty for nontraumatic osteonecrosis of the femoral head
J Orthop Sci (2008) 13:116–121 DOI 10.1007/s00776-007-1208-0
Original article Quality of life following femoral osteotomy and total hip arthroplasty for nontraumatic osteonecrosis of the femoral head TAISUKE SEKI1, YUKIHARU HASEGAWA1, TETSUO MASUI1, JIN YAMAGUCHI1, TOSHIYA KANOH1, NAOKI ISHIGURO1, and KIYOHARU KAWABE2 1 2
Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan Department of Orthopedic Surgery, Aichi-ken Saiseikai Hospital, Nagoya, Japan
Abstract Background. Nontraumatic osteonecrosis of the femoral head (NOFH) frequently develops in active young persons. The affected femoral head collapses owing to weight-bearing, and the individual’s quality of life (QOL) can be predicted to deteriorate greatly with time. We undertook to determine the efficacy of surgery and to clarify whether patient QOL differs according to differences in the surgical method employed. Methods. We cross-sectionally compared QOL in NOFH patients treated with femoral osteotomy, total hip arthroplasty (THA), or nonoperatively. A total of 81 cases were available for study, comprising 41 with osteotomy, 19 with THA, and 21 in the nonoperative group. The mean age was significantly higher in the THA group than in the other two groups. The Japanese Orthopaedic Association (JOA) hip score and Visual Analogue Scale (VAS) regarding hip pain were compared among the groups. These groups were also analyzed for their health-related QOL using the Short Form Health Survey (SF-36) with analysis of variance for age adjustment. Results. The mean JOA score was significantly lower in the nonoperative group than in the osteotomy group. The mean VAS scores showed no significant difference between any of the three groups. Regarding the subscales of SF-36, the physical functioning subscale in the nonoperative group showed a significantly lower value than was seen in the osteotomy group (P = 0.003). The physical component summary (PCS) scores were 39.4 (osteotomy group), 39.1 (THA group), and 27.8 (nonoperative group), with a significant difference between the osteotomy and nonoperative groups (P = 0.027). There was also a trend for a better PCS scores in the THA group than in the nonoperative group (P = 0.056). The mental component summary scores were 49.6 (osteotomy group), 50.3 (THA group), and 48.3 (nonoperative group), with no significant difference found among any of the three groups. Conclusions. Among patients with NOFH, physical function impairment was a more potent factor than pain for decreasing QOL in the nonoperative group than in the surgical groups. Furthermore, osteotomy and THA were similar in regard to
Offprint requests to: T. Seki Received: August 17, 2007 / Accepted: December 17, 2007
the evaluation of the postoperative QOL score if the indications for osteotomy were strictly applied.
Introduction Nontraumatic osteonecrosis of the femoral head (NOFH) is a condition in which impaired blood flow to the femoral head results in avascular necrosis. The affected femoral head becomes painful as a result of subchondral bone collapse due to weight-bearing. Furthermore, worsening of congruency due to deformity of the femoral head promotes the progression of NOFH to osteoarthritis of the hip.1,2 As a result of these changes the daily activities of patients become severely restricted. This disease frequently develops in highly active young persons; and because of differences in the underlying factors, the optimal treatment has yet to be established, with differences in the surgical results also influenced by the degree of progression of NOFH. During the early stage, osteotomy is indicated for joint preservation by preventing collapse of the necrotic portion and achieving stability with regard to weightbearing.3,4 On the other hand, in cases in which femoral head collapse has progressed or osteoarthritis of the hip has developed, total hip arthroplasty (THA) is recommended.3 For osteotomy aiming at joint preservation, weight-bearing is dispersed by changing the shape of the native bone; by preventing collapse of the necrotic bone and promoting repair, results close to those of regenerative therapy can be anticipated. Because the patients affected by NOFH are generally younger than patients with osteoarthritis of the hip, and given their long course, the quality of life (QOL) of these patients can be predicted to deteriorate greatly with time. In cases in which the affected site is small, avoidance of THA and osteotomy aiming at joint preservation to delay the timing of eventual THA is an option.5 The degree of pain relief achieved with THA
T. Seki et al.: QOL with femur head necrosis
117
is satisfactory, and recovery of physical activities during the early postoperative period can be expected. However, there are limits to the durability of the implant used for hip arthroplasty, and in young persons the need for future revision is a major problem.6 These therapies have traditionally been objectively evaluated from the physicians’ viewpoint, but their efficacy also needs to be determined from the standpoint of the patients. For this purpose, we need to assess the influence of the disease on patients not only by objective indices but also by evaluating patient QOL indices. The natural course and surgical therapy of NOFH have previously been reported,7,8 but few studies have also assessed patient QOL.9 Femoral head-preserving procedures have been frequently reported in Japan.4,11,12 Our institution is one of the osteotomy centers in Japan, and many patients requiring osteotomy are referred to us. Accordingly, we have focused on QOL comparing osteotomy and THA. In this study, by comparing QOL in NOFH patients divided into femoral osteotomy and THA surgical groups and a nonoperative group, we undertook to determine the efficacy of these surgeries and clarify whether patient QOL differs according to differences in the surgical method employed.
Patients and methods During the period from November 2005 to May 2006, a self-administered questionnaire was presented to 316 patients consulting at our hospital and affiliated hospital. The aim of the study was explained to each patient, and informed consent to participate was obtained in
writing. Because this investigation was undertaken as a part of clinical observation and was not interventional in nature, it did not require permission of our institutional review board. The questionnaire was filled out by the patient while waiting in the outpatient clinic and was then collected by the person in charge or directly returned by the patient. Of the 316 patients, 198 had osteoarthritis of the hip, 95 had NOFH, and 23 had other conditions. Here we focused on the 95 patients with NOFH after dividing them into an osteotomy group, a THA group, and a nonoperative group. Four patients with many missing laboratory values, three who underwent pedicle bone grafting, and seven who were seen less than 6 months after surgery were excluded for the purposes of this study. No patients in the osteotomy and THA groups required additional surgery. Finally, 81 cases were available for study, comprising 41 in the osteotomy group, 19 in the THA group, and 21 in the nonoperative group (Table 1). Core decompression was not performed in our hospital. The mean age was significantly higher in the THA group than in the other two groups (P = 0.001). Sex distribution did not differ significantly among the three groups (chi-squared test). Of the total 81 cases, the underlying cause of NOFH was alcohol in 26 cases, steroids in 35, both in 6, and idiopathic in 14. The type and stage of NOFH were classified according to the Japanese investigation criteria for idiopathic osteonecrosis of the femoral head.10 The type and stage of each group are listed in Table 2. Osteotomy was indicated in young persons who did not show progression to osteoarthritis of the hip. The
Table 1. Demographics of patients with nontraumatic osteonecrosis of the femoral head Parameter No. of patients Age (years), mean ± SD Male/female Etiology Alcohol abuse Steroid-induced Alcohol and steroids Idiopathic Follow-up (mean years) After first visit After surgery JOA score (mean ± SD) VAS (mean ± SD)
THA
Nonoperative treatment
19 57.1 ± 14.7* 14/5
21 45.7 ± 10.7 11/10
Osteotomy 41 43.7 ± 11.6 32/9 15 17 2 7 6.0 5.2 86.7 ± 12.9** 24.5 ± 25.3
5 7 3 4 5.7 4.1 81.3 ± 14.2 25.6 ± 28.3
6 11 1 3 5.8 N/A 75.1 ± 14.6 28.7 ± 32.1
THA, total hip arthroplasty; JOA score, Japanese Orthopaedic Association hip score; VAS, Visual Analogue Scale regarding hip pain; N/A, not available * P < 0.01 significant difference (THA vs. osteotomy and nonoperative group) ** P < 0.01 significant difference (osteotomy vs. nonoperative group)
118
T. Seki et al.: QOL with femur head necrosis
Table 2. Classification and staging of osteonecrosis of the femoral head according to JOA classification (2001) Osteotomy
THA
Nonoperative treatment
Type A B C1 C2 Total
0 6 19 16 41
0 2 5 12 19
1 2 9 9 21
Stage 1 2 3A 3B 4 Total
1 17 6 8 9 41
0 2 2 11 4 19
1 4 1 11 4 21
Parameter
The preoperative data of the osteotomy and THA groups are shown. The nonoperative group was decided at the initial consultation
indications for curved varus osteotomy (CVO) were type B and C1 or C2 with an intact area of the femoral head that measured less than 36% in Lauenstein’s view but more than 30% on the weight-bearing portion in the anteroposterior view in maximum abduction. From 2001, the indications for curved varus osteotomy were extended to those with an intact area of more than 20% of the weight-bearing portion in maximum abduction.11 In cases in which on varus osteotomy the covering femoral head was seen to be inadequate or in which more extensive necrosis was present, femoral head transtrochanteric rotational osteotomy (TRO) was performed.4,12 The osteotomy group (n = 41) comprised 14 CVOs and 27 TROs. There were 17 patients with ≥ stage 3B due to collapse of the femoral head (CVO 4 cases, TRO 13 cases). The THA group (n = 19) included patients in whom stage 3 femoral head collapse was found, those in whom extensive necrosis precluded osteotomy despite being in a precollapse state (stage 2), and patients who were terminal and whose disease had progressed to osteoarthritis (OA) (stage 4). In all cases, the osteotomy and THA procedures were first-time operations. The mean postoperative followup period was 5.2 years in the osteotomy group and 4.1 years in the THA group. The difference in the mean postoperative follow-up period between osteotomy and THA groups was not significant. The nonoperative group (n = 21) comprised patients not subjected to surgical intervention and included some who underwent medical therapy and/or restriction of weight-bearing. In this group, 4 patients had stage ≥3 progressive disease but could not undergo surgery because of worsening of the primary disease; another 12 patients did not desire surgery.
Clinical assessment To evaluate QOL we used the Short-Form 36 Health Survey (SF-36 Japanese version 2).13 In addition, to evaluate hip pain we used a Visual Analogue Scale (VAS). The VAS demonstrates the degree of pain by having the patient place a mark on a 0- to 100-mm line; complete absence of pain is indicated by a mark placed at the left edge, at 0 mm; and maximum pain is indicated by a mark placed at the right edge, at 100 mm. Also, at outpatient appointments, the physician obtained a history, noted relevant physical findings, and then recorded them in the patient’s chart according to the Japan Orthopaedic Association (JOA) hip score.14 Each patient’s JOA score was obtained from this record. The JOA score encompasses pain (0–40), gait (0–20), activities of daily living (0–20), and range of motion (0–20). The possible range of values is 0–100, with the higher values reflecting a better state. The JOA score and the VAS were compared among the osteotomy, THA, and nonoperative groups; and using the SF-36 to assess QOL, eight SF-36 subscales were determined. In addition, SF-36 was converted to a summary score, which represents physical and mental health, and the results were compared among the groups.15 Considering a score of 50 on each subscale to represent the Japanese population norm, the scores were adjusted so a change in the score of 10 would be 1 standard deviation (SD). Statistical analysis The SPSS statistical package (version 11.0) was used for the statistical analysis. The Kruskal-Wallis test was used to analyze the JOA score and VAS. Analysis of variance (ANOVA) was used for comparisons of each SF36 subscale among the three groups. It was recognized that age exerts an influence on this QOL, so we investigated differences in the QOL score among the three groups after adjusting for bias in age. Group comparisons were adjusted for age, in the case of ANOVA, with Bonferroni’s correction performed for multiple comparisons. Spearman’s correlation was used to determine the correlation between the JOA score and SF-36 summary scores. A statistically significant difference was defined as P < 0.05.
Results At the time of the investigation the mean JOA score was 86.7 in the osteotomy group, 81.3 in the THA group, and 75.1 in the nonoperative group, with the score significantly lower in the nonoperative group than in the osteotomy group. The mean VAS score was 24.5 in the
T. Seki et al.: QOL with femur head necrosis
119 * p = 0.027
score
100 **
80
osteotomy THA non-operative
score 70
p = 0.056
N.S.
60
osteotomy THA non-operative
50
60
40
40 30
20 0
20 10
PF RP BP GH VT SF RE MH
Fig. 1. Comparison of the Short-Form Health Survey (SF-36) subscales adjusted by age for each group of nontraumatic osteonecrosis of the femoral head. PF, physical functioning; RP, role physical; BP, bodily pain; GH, general health perceptions; VT, vitality; SF, social functioning; RE, role emotional; MH, mental health. **P = 0.003 (significant difference). Group comparisons were adjusted for age
osteotomy group, 25.6 in the THA group, and 28.7 in the nonoperative group, with no significant differences noted among any of the three groups (P = 0.985) (Table 1). Regarding the eight subscales of SF-36, in the nonoperative group all subscales were lower than those in the osteotomy and THA groups. The physical functioning (PF) subscale in the nonoperative group showed a statistically significantly lower value than that in the osteotomy group (P = 0.003), with the influence of physical functional disturbance being more marked than that of pain in the nonoperative group (Fig. 1). The physical component summary score (PCS), which represents physical health, was 39.4 in the osteotomy group, 39.1 in the THA group, and 27.8 in the nonoperative group, with a significant difference found between the osteotomy and nonoperative groups (Fig. 2). There was also a trend for better PCS scores in the THA group than in the nonoperative group, but the difference was not statistically significant (P = 0.056). On the other hand, the mental component summary score (MCS), which represents mental health, was 49.6 in the osteotomy group, 50.3 in the THA group, and 48.3 in the nonoperative group, with no significant difference found among any of the three groups. These results demonstrate that all three groups had scores equivalent to the Japanese population norm of 50, indicating that their mental health has not been affected. Furthermore, although a significant strong correlation was noted between the JOA score as evaluated from the physician side and PCS in all three groups, a significant correlation was not found with MCS (Table 3).
0
PCS
MCS
Fig. 2. Age-adjusted SF-36 summary score of nontraumatic osteonecrosis of the femoral head. PCS, physical component summary; MCS, mental component summary. *P < 0.05 significant difference; N.S., not significant. 50 = Japanese population norm; 10 = standard deviation (SD). Group comparisons were adjusted for age. Error bar is the SD
Table 3. Correlation coefficients between JOA score and SF-36 summary scores Correlation (r) Parameter SF-36 PCS MCS
Osteotomy
THA
Nonoperative treatment
0.662* 0.191
0.749* 0.205
0.785* 0.413
SF-36, Short-Term Health Survey; PCS, physical component summary; MCS, mental component summary * P < 0.01 significant difference (Spearman’s correlation)
We also categorized patient age into three groups — 20–39 years, 40–59 years, and 60–80 years — and calculated the corresponding SF-36 scores (Fig. 3). For the SF-36 subscales, the differences between age categories for the three groups were not statistically significant.
Discussion Recently, there has been heightened interest in evaluating patient QOL, reflected in reports focused on QOL after hip surgery, which have been increasing in number. Regarding specific surgical methods, numerous reports have described QOL after THA,16,17 whereas only a few have focused on QOL after osteotomy.18 In these reports, osteoarthritis of the hip was the main condition present, but almost no studies have focused on NOFH alone. In Japan, the number of new-onset cases of
120
T. Seki et al.: QOL with femur head necrosis Osteotomy
THA
non-operative
100
100
100
75
75
75
50
50
25
25
50
25
PF RP BP GH VT SF RE MH
PF RP BP GH VT SF RE MH
PF RP BP GH VT SF RE MH
age category 39y⭌ 40-59y 60y⬉
NOFH is estimated to amount to approximately 2500 per year, with most being attributable to alcohol or steroid use. However, because of the small number of persons affected, the number of cases experienced at each institution is limited, precluding adequate evaluation. In this study, the QOL of NOFH patients was investigated cross-sectionally, with the nonoperative group showing lower scores for all eight of the SF-36 subscales than were seen in the osteotomy and THA groups. In particular, the PF subscale of the nonoperative group showed a statistically significantly lower value compared to osteotomy group. No significant difference was noted between the three groups in the VAS regarding hip pain. This result was thought to be due to the fact that in the nonoperative group the influence of physical functional disturbance was more marked than that of pain. In the study on the SF-36 summary score, the PCS score was significantly better in the osteotomy group than in the nonoperative group. This superior result, compared to the other groups, was ascribed to the fact that following osteotomy bone fusion occurs and bone metabolism normalizes, allowing the hip to function as living bone; thus, there is less anxiety about dislocation than in patients with THA. On the other hand, as assessed by the MCS score, the mental health of all three groups was similar to the Japanese population norm. This may be due to the fact that in chronic conditions such as NOFH many patients show a change in their perception of pain, and even in the presence of functional disturbance they are able to adjust to their new circumstances, thereby maintaining greater mental stability than might be expected. As a result, the fact that a significant difference was detected between the osteotomy and nonoperative groups on the physical function scale whereas no differences were found between the three groups in the SF-36 mental component score can be attributed to differ-
Fig. 3. SF-36 subscale scores distributed in age categories for nontraumatic osteonecrosis of the femoral head
ences in the activities of daily living (ADL) and degree of pain being reflected in the QOL score alone. The JOA score is employed as an objective evaluation method from the viewpoint of the physician, whereas the SF-36 is a health-related QOL survey based on the patient’s subjective experience. From the correlation coefficients of the two scores, the JOA score showed a significant correlation with mainly the physical health aspects of the SF-36 in each of the three groups but not with the mental health aspect (Table 3). These findings reflect the fact that with disease-specific evaluation and general health evaluations dissociations may be noted in the physical and mental aspects. Because relying on the JOA score alone does not permit evaluation of patients’ mental health, combined use of the SF-36 facilitates more detailed assessment of a patient’s total state. Regarding the choice of surgical method, Wiklund et al. described that THA, by mitigating pain and improving function, achieves a postoperative QOL similar to that of healthy persons.19 Nakai et al., in a survey of 37 patients with femoral head necrosis, concluded that, compared to osteotomy TRO, THA more reliably enhanced patient QOL9. However, in the present study, the SF-36 score of the osteotomy and THA groups did not differ significantly from that of the patients undergoing THA, with a stable QOL maintained. This may be explained by the fact that our hospital is an osteotomy center that has performed numerous such operations with stable results.11,20,21 If the indications for osteotomy are strictly adhered to and techniques carefully practiced, we believe that results as good as those of THA can be achieved. This study has several limitations. The first is that being a cross-sectional study a continuous evaluation could not be performed. Because we obtained QOL data from a survey conducted during a given period on a cross-sectional basis, the data of the osteotomy and
T. Seki et al.: QOL with femur head necrosis
THA groups are from the postoperative period, with differences noted in the length of the postoperative period in individual patients. However, no significant difference in the mean postoperative follow-up period was noted between the two groups in which these operations were conducted. On the other hand, evaluation of the mean follow-up period was considered to commence at the point after the initial presentation at which femoral head osteonecrosis was first diagnosed. It must be noted that accurately identifying the onset is difficult because femoral head osteonecrosis is asymptomatic in a considerable number of cases at the onset, and so many patients do not present to the hospital at this time. The second limitation is that because of the small number of NOFH cases we could not match for type and stage in each group. The third limitation is the fact that, with regard to the type of operation chosen, age and surgical conditions that influence the indications for osteotomy and THA differ. Therefore, it is difficult to compare clinical results. Finally, the nonoperative group included cases in which surgery was precluded because of the presence of co-morbidities or other reasons, which themselves may have decreased the QOL score. However, the fact that the postosteotomy QOL was assessed as being equivalent to that of THA may provide important information when making comparisons with patients undergoing conservative therapy or deciding on which surgical method to select. In future, long-term longitudinal studies addressing these issues are needed. Conclusions We grouped 81 patients with nontraumatic osteonecrosis of the femoral head into two surgical groups (femoral osteotomy or THA) and a nonoperative group and evaluated their health-related QOL using SF-36. In the nonoperative group, compared to the surgical groups, physical function impairment was a more potent factor than pain for decreasing QOL. Regarding the evaluation of the postoperative QOL score, osteotomy and THA give similar QOL results if the indication for osteotomy are strictly applied. References 1. Daniel M, Herman S, Dolinar D, Iglic A, Sochor M, Kralj-Iglic V. Contact stress in hips with osteonecrosis of the femoral head. Clin Orthop 2006;447:92–9.
121 2. Ficat RP. Idiopathic bone necrosis of the femoral head: early diagnosis and treatment. J Bone Joint Surg Br 1985;67:3–9. 3. Mont MA, Jones LC, Hungerford DS. Nontraumatic osteonecrosis of the femoral head: ten years later. J Bone Joint Surg Am 2006;88:1117–32. 4. Sugioka Y. Transtrochanteric anterior rotational osteotomy of the femoral head in the treatment of osteonecrosis affecting the hip: a new osteotomy operation. Clin Orthop 1978;130:191–201. 5. Shannon BD, Trousdale RT. Femoral osteotomies for avascular necrosis of the femoral head. Clin Orthop 2004;418:34–40. 6. Eskelinen A, Remes V, Helenius I, Pulkkinen P, Nevalainen J, Paavolainen P. Total hip arthroplasty for primary osteoarthrosis in younger patients in the Finnish arthroplasty register: 4,661 primary replacements followed for 0–22 years. Acta Orthop 2005;76:28–41. 7. Ito H, Matsuno T, Omizu N, Aoki Y, Minami A. Mid-term prognosis of non-traumatic osteonecrosis of the femoral head. J Bone Joint Surg Br 2003;85:796–801. 8. Jergesen HE, Khan AS. The natural history of untreated asymptomatic hips in patients who have non-traumatic osteonecrosis. J Bone Joint Surg Am 1997;79:359–63. 9. Nakai T, Masuhara K, Matsui M, Ohzono K, Ochi T. Therapeutic effect of transtrochanteric rotational osteotomy and hip arthroplasty on quality of life of patients with osteonecrosis. Arch Orthop Trauma Surg 2000;120:252–4. 10. Sugano N, Atsumi T, Ohzono K, Kubo T, Hotokebuchi T, Takaoka K. The 2001 revised criteria for diagnosis, classification, and staging of idiopathic osteonecrosis of the femoral head. J Orthop Sci 2002;7:601–5. 11. Sakano S, Hasegawa Y, Torii Y, Kawasaki M, Ishiguro N. Curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head. J Bone Joint Surg Br 2004;86:359–65. 12. Atsumi T, Kajiwara T, Hiranuma Y, Tamaoki S, Asakura Y. Posterior rotational osteotomy for nontraumatic osteonecrosis with extensive collapsed lesions in young patients. J Bone Joint Surg Am 2006;88(suppl. 3):42–7. 13. Fukuhara S, Bito S, Green J, Hsiao A, Kurokawa K. Translation, adaptation, and validation of the SF-36 Health Survey for use in Japan. J Clin Epidemiol 1998;51:1037–44. 14. Takeda H, Kamogawa J, Sakayama K, Kamada K, Tanaka S, Yamamoto H. Evaluation of clinical prognosis and activities of daily living using functional independence measure in patients with hip fractures. J Orthop Sci 2006;11:584–91. 15. Ware JE, Kosinski M. Interpreting SF-36 summary health measures: a response. Qual Life Res 2001;10:405–13. 16. Beaule PE, Dorey FJ, Hoke R, Leduff M, Amstutz HC. The value of patient activity level in the outcome of total hip arthroplasty. J Arthroplasty 2006;21:547–52. 17. Wood GC, McLauchlan GJ. Outcome assessment in the elderly after total hip arthroplasty. J Arthroplasty 2006;21:398–404. 18. Kawasaki M, Hasegawa Y, Sakano S, Torii Y, Warashina H. Quality of life after several treatments for osteoarthritis of the hip. J Orthop Sci 2003;8:32–5. 19. Wiklund I, Romanus B. A comparison of quality of life before and after arthroplasty in patients who had arthrosis of the hip joint. J Bone Joint Surg Am 1991;73:765–9. 20. Hasegawa Y, Sakano S, Iwase T, Iwasada S, Torii S, Iwata H. Pedicle bone grafting versus transtrochanteric rotational osteotomy for avascular necrosis of the femoral head. J Bone Joint Surg Br 2003;85:191–8. 21. Iwasada S, Hasegawa Y, Iwase T, Kitamura S, Iwata H. Transtrochanteric rotational osteotomy for osteonecrosis of the femoral head: 43 patients followed for at least 3 years. Arch Orthop Trauma Surg 1997;116:447–53.
Original article Quality of life following femoral osteotomy and total hip arthroplasty for nontraumatic osteonecrosis of the femoral head TAISUKE SEKI1, YUKIHARU HASEGAWA1, TETSUO MASUI1, JIN YAMAGUCHI1, TOSHIYA KANOH1, NAOKI ISHIGURO1, and KIYOHARU KAWABE2 1 2
Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan Department of Orthopedic Surgery, Aichi-ken Saiseikai Hospital, Nagoya, Japan
Abstract Background. Nontraumatic osteonecrosis of the femoral head (NOFH) frequently develops in active young persons. The affected femoral head collapses owing to weight-bearing, and the individual’s quality of life (QOL) can be predicted to deteriorate greatly with time. We undertook to determine the efficacy of surgery and to clarify whether patient QOL differs according to differences in the surgical method employed. Methods. We cross-sectionally compared QOL in NOFH patients treated with femoral osteotomy, total hip arthroplasty (THA), or nonoperatively. A total of 81 cases were available for study, comprising 41 with osteotomy, 19 with THA, and 21 in the nonoperative group. The mean age was significantly higher in the THA group than in the other two groups. The Japanese Orthopaedic Association (JOA) hip score and Visual Analogue Scale (VAS) regarding hip pain were compared among the groups. These groups were also analyzed for their health-related QOL using the Short Form Health Survey (SF-36) with analysis of variance for age adjustment. Results. The mean JOA score was significantly lower in the nonoperative group than in the osteotomy group. The mean VAS scores showed no significant difference between any of the three groups. Regarding the subscales of SF-36, the physical functioning subscale in the nonoperative group showed a significantly lower value than was seen in the osteotomy group (P = 0.003). The physical component summary (PCS) scores were 39.4 (osteotomy group), 39.1 (THA group), and 27.8 (nonoperative group), with a significant difference between the osteotomy and nonoperative groups (P = 0.027). There was also a trend for a better PCS scores in the THA group than in the nonoperative group (P = 0.056). The mental component summary scores were 49.6 (osteotomy group), 50.3 (THA group), and 48.3 (nonoperative group), with no significant difference found among any of the three groups. Conclusions. Among patients with NOFH, physical function impairment was a more potent factor than pain for decreasing QOL in the nonoperative group than in the surgical groups. Furthermore, osteotomy and THA were similar in regard to
Offprint requests to: T. Seki Received: August 17, 2007 / Accepted: December 17, 2007
the evaluation of the postoperative QOL score if the indications for osteotomy were strictly applied.
Introduction Nontraumatic osteonecrosis of the femoral head (NOFH) is a condition in which impaired blood flow to the femoral head results in avascular necrosis. The affected femoral head becomes painful as a result of subchondral bone collapse due to weight-bearing. Furthermore, worsening of congruency due to deformity of the femoral head promotes the progression of NOFH to osteoarthritis of the hip.1,2 As a result of these changes the daily activities of patients become severely restricted. This disease frequently develops in highly active young persons; and because of differences in the underlying factors, the optimal treatment has yet to be established, with differences in the surgical results also influenced by the degree of progression of NOFH. During the early stage, osteotomy is indicated for joint preservation by preventing collapse of the necrotic portion and achieving stability with regard to weightbearing.3,4 On the other hand, in cases in which femoral head collapse has progressed or osteoarthritis of the hip has developed, total hip arthroplasty (THA) is recommended.3 For osteotomy aiming at joint preservation, weight-bearing is dispersed by changing the shape of the native bone; by preventing collapse of the necrotic bone and promoting repair, results close to those of regenerative therapy can be anticipated. Because the patients affected by NOFH are generally younger than patients with osteoarthritis of the hip, and given their long course, the quality of life (QOL) of these patients can be predicted to deteriorate greatly with time. In cases in which the affected site is small, avoidance of THA and osteotomy aiming at joint preservation to delay the timing of eventual THA is an option.5 The degree of pain relief achieved with THA
T. Seki et al.: QOL with femur head necrosis
117
is satisfactory, and recovery of physical activities during the early postoperative period can be expected. However, there are limits to the durability of the implant used for hip arthroplasty, and in young persons the need for future revision is a major problem.6 These therapies have traditionally been objectively evaluated from the physicians’ viewpoint, but their efficacy also needs to be determined from the standpoint of the patients. For this purpose, we need to assess the influence of the disease on patients not only by objective indices but also by evaluating patient QOL indices. The natural course and surgical therapy of NOFH have previously been reported,7,8 but few studies have also assessed patient QOL.9 Femoral head-preserving procedures have been frequently reported in Japan.4,11,12 Our institution is one of the osteotomy centers in Japan, and many patients requiring osteotomy are referred to us. Accordingly, we have focused on QOL comparing osteotomy and THA. In this study, by comparing QOL in NOFH patients divided into femoral osteotomy and THA surgical groups and a nonoperative group, we undertook to determine the efficacy of these surgeries and clarify whether patient QOL differs according to differences in the surgical method employed.
Patients and methods During the period from November 2005 to May 2006, a self-administered questionnaire was presented to 316 patients consulting at our hospital and affiliated hospital. The aim of the study was explained to each patient, and informed consent to participate was obtained in
writing. Because this investigation was undertaken as a part of clinical observation and was not interventional in nature, it did not require permission of our institutional review board. The questionnaire was filled out by the patient while waiting in the outpatient clinic and was then collected by the person in charge or directly returned by the patient. Of the 316 patients, 198 had osteoarthritis of the hip, 95 had NOFH, and 23 had other conditions. Here we focused on the 95 patients with NOFH after dividing them into an osteotomy group, a THA group, and a nonoperative group. Four patients with many missing laboratory values, three who underwent pedicle bone grafting, and seven who were seen less than 6 months after surgery were excluded for the purposes of this study. No patients in the osteotomy and THA groups required additional surgery. Finally, 81 cases were available for study, comprising 41 in the osteotomy group, 19 in the THA group, and 21 in the nonoperative group (Table 1). Core decompression was not performed in our hospital. The mean age was significantly higher in the THA group than in the other two groups (P = 0.001). Sex distribution did not differ significantly among the three groups (chi-squared test). Of the total 81 cases, the underlying cause of NOFH was alcohol in 26 cases, steroids in 35, both in 6, and idiopathic in 14. The type and stage of NOFH were classified according to the Japanese investigation criteria for idiopathic osteonecrosis of the femoral head.10 The type and stage of each group are listed in Table 2. Osteotomy was indicated in young persons who did not show progression to osteoarthritis of the hip. The
Table 1. Demographics of patients with nontraumatic osteonecrosis of the femoral head Parameter No. of patients Age (years), mean ± SD Male/female Etiology Alcohol abuse Steroid-induced Alcohol and steroids Idiopathic Follow-up (mean years) After first visit After surgery JOA score (mean ± SD) VAS (mean ± SD)
THA
Nonoperative treatment
19 57.1 ± 14.7* 14/5
21 45.7 ± 10.7 11/10
Osteotomy 41 43.7 ± 11.6 32/9 15 17 2 7 6.0 5.2 86.7 ± 12.9** 24.5 ± 25.3
5 7 3 4 5.7 4.1 81.3 ± 14.2 25.6 ± 28.3
6 11 1 3 5.8 N/A 75.1 ± 14.6 28.7 ± 32.1
THA, total hip arthroplasty; JOA score, Japanese Orthopaedic Association hip score; VAS, Visual Analogue Scale regarding hip pain; N/A, not available * P < 0.01 significant difference (THA vs. osteotomy and nonoperative group) ** P < 0.01 significant difference (osteotomy vs. nonoperative group)
118
T. Seki et al.: QOL with femur head necrosis
Table 2. Classification and staging of osteonecrosis of the femoral head according to JOA classification (2001) Osteotomy
THA
Nonoperative treatment
Type A B C1 C2 Total
0 6 19 16 41
0 2 5 12 19
1 2 9 9 21
Stage 1 2 3A 3B 4 Total
1 17 6 8 9 41
0 2 2 11 4 19
1 4 1 11 4 21
Parameter
The preoperative data of the osteotomy and THA groups are shown. The nonoperative group was decided at the initial consultation
indications for curved varus osteotomy (CVO) were type B and C1 or C2 with an intact area of the femoral head that measured less than 36% in Lauenstein’s view but more than 30% on the weight-bearing portion in the anteroposterior view in maximum abduction. From 2001, the indications for curved varus osteotomy were extended to those with an intact area of more than 20% of the weight-bearing portion in maximum abduction.11 In cases in which on varus osteotomy the covering femoral head was seen to be inadequate or in which more extensive necrosis was present, femoral head transtrochanteric rotational osteotomy (TRO) was performed.4,12 The osteotomy group (n = 41) comprised 14 CVOs and 27 TROs. There were 17 patients with ≥ stage 3B due to collapse of the femoral head (CVO 4 cases, TRO 13 cases). The THA group (n = 19) included patients in whom stage 3 femoral head collapse was found, those in whom extensive necrosis precluded osteotomy despite being in a precollapse state (stage 2), and patients who were terminal and whose disease had progressed to osteoarthritis (OA) (stage 4). In all cases, the osteotomy and THA procedures were first-time operations. The mean postoperative followup period was 5.2 years in the osteotomy group and 4.1 years in the THA group. The difference in the mean postoperative follow-up period between osteotomy and THA groups was not significant. The nonoperative group (n = 21) comprised patients not subjected to surgical intervention and included some who underwent medical therapy and/or restriction of weight-bearing. In this group, 4 patients had stage ≥3 progressive disease but could not undergo surgery because of worsening of the primary disease; another 12 patients did not desire surgery.
Clinical assessment To evaluate QOL we used the Short-Form 36 Health Survey (SF-36 Japanese version 2).13 In addition, to evaluate hip pain we used a Visual Analogue Scale (VAS). The VAS demonstrates the degree of pain by having the patient place a mark on a 0- to 100-mm line; complete absence of pain is indicated by a mark placed at the left edge, at 0 mm; and maximum pain is indicated by a mark placed at the right edge, at 100 mm. Also, at outpatient appointments, the physician obtained a history, noted relevant physical findings, and then recorded them in the patient’s chart according to the Japan Orthopaedic Association (JOA) hip score.14 Each patient’s JOA score was obtained from this record. The JOA score encompasses pain (0–40), gait (0–20), activities of daily living (0–20), and range of motion (0–20). The possible range of values is 0–100, with the higher values reflecting a better state. The JOA score and the VAS were compared among the osteotomy, THA, and nonoperative groups; and using the SF-36 to assess QOL, eight SF-36 subscales were determined. In addition, SF-36 was converted to a summary score, which represents physical and mental health, and the results were compared among the groups.15 Considering a score of 50 on each subscale to represent the Japanese population norm, the scores were adjusted so a change in the score of 10 would be 1 standard deviation (SD). Statistical analysis The SPSS statistical package (version 11.0) was used for the statistical analysis. The Kruskal-Wallis test was used to analyze the JOA score and VAS. Analysis of variance (ANOVA) was used for comparisons of each SF36 subscale among the three groups. It was recognized that age exerts an influence on this QOL, so we investigated differences in the QOL score among the three groups after adjusting for bias in age. Group comparisons were adjusted for age, in the case of ANOVA, with Bonferroni’s correction performed for multiple comparisons. Spearman’s correlation was used to determine the correlation between the JOA score and SF-36 summary scores. A statistically significant difference was defined as P < 0.05.
Results At the time of the investigation the mean JOA score was 86.7 in the osteotomy group, 81.3 in the THA group, and 75.1 in the nonoperative group, with the score significantly lower in the nonoperative group than in the osteotomy group. The mean VAS score was 24.5 in the
T. Seki et al.: QOL with femur head necrosis
119 * p = 0.027
score
100 **
80
osteotomy THA non-operative
score 70
p = 0.056
N.S.
60
osteotomy THA non-operative
50
60
40
40 30
20 0
20 10
PF RP BP GH VT SF RE MH
Fig. 1. Comparison of the Short-Form Health Survey (SF-36) subscales adjusted by age for each group of nontraumatic osteonecrosis of the femoral head. PF, physical functioning; RP, role physical; BP, bodily pain; GH, general health perceptions; VT, vitality; SF, social functioning; RE, role emotional; MH, mental health. **P = 0.003 (significant difference). Group comparisons were adjusted for age
osteotomy group, 25.6 in the THA group, and 28.7 in the nonoperative group, with no significant differences noted among any of the three groups (P = 0.985) (Table 1). Regarding the eight subscales of SF-36, in the nonoperative group all subscales were lower than those in the osteotomy and THA groups. The physical functioning (PF) subscale in the nonoperative group showed a statistically significantly lower value than that in the osteotomy group (P = 0.003), with the influence of physical functional disturbance being more marked than that of pain in the nonoperative group (Fig. 1). The physical component summary score (PCS), which represents physical health, was 39.4 in the osteotomy group, 39.1 in the THA group, and 27.8 in the nonoperative group, with a significant difference found between the osteotomy and nonoperative groups (Fig. 2). There was also a trend for better PCS scores in the THA group than in the nonoperative group, but the difference was not statistically significant (P = 0.056). On the other hand, the mental component summary score (MCS), which represents mental health, was 49.6 in the osteotomy group, 50.3 in the THA group, and 48.3 in the nonoperative group, with no significant difference found among any of the three groups. These results demonstrate that all three groups had scores equivalent to the Japanese population norm of 50, indicating that their mental health has not been affected. Furthermore, although a significant strong correlation was noted between the JOA score as evaluated from the physician side and PCS in all three groups, a significant correlation was not found with MCS (Table 3).
0
PCS
MCS
Fig. 2. Age-adjusted SF-36 summary score of nontraumatic osteonecrosis of the femoral head. PCS, physical component summary; MCS, mental component summary. *P < 0.05 significant difference; N.S., not significant. 50 = Japanese population norm; 10 = standard deviation (SD). Group comparisons were adjusted for age. Error bar is the SD
Table 3. Correlation coefficients between JOA score and SF-36 summary scores Correlation (r) Parameter SF-36 PCS MCS
Osteotomy
THA
Nonoperative treatment
0.662* 0.191
0.749* 0.205
0.785* 0.413
SF-36, Short-Term Health Survey; PCS, physical component summary; MCS, mental component summary * P < 0.01 significant difference (Spearman’s correlation)
We also categorized patient age into three groups — 20–39 years, 40–59 years, and 60–80 years — and calculated the corresponding SF-36 scores (Fig. 3). For the SF-36 subscales, the differences between age categories for the three groups were not statistically significant.
Discussion Recently, there has been heightened interest in evaluating patient QOL, reflected in reports focused on QOL after hip surgery, which have been increasing in number. Regarding specific surgical methods, numerous reports have described QOL after THA,16,17 whereas only a few have focused on QOL after osteotomy.18 In these reports, osteoarthritis of the hip was the main condition present, but almost no studies have focused on NOFH alone. In Japan, the number of new-onset cases of
120
T. Seki et al.: QOL with femur head necrosis Osteotomy
THA
non-operative
100
100
100
75
75
75
50
50
25
25
50
25
PF RP BP GH VT SF RE MH
PF RP BP GH VT SF RE MH
PF RP BP GH VT SF RE MH
age category 39y⭌ 40-59y 60y⬉
NOFH is estimated to amount to approximately 2500 per year, with most being attributable to alcohol or steroid use. However, because of the small number of persons affected, the number of cases experienced at each institution is limited, precluding adequate evaluation. In this study, the QOL of NOFH patients was investigated cross-sectionally, with the nonoperative group showing lower scores for all eight of the SF-36 subscales than were seen in the osteotomy and THA groups. In particular, the PF subscale of the nonoperative group showed a statistically significantly lower value compared to osteotomy group. No significant difference was noted between the three groups in the VAS regarding hip pain. This result was thought to be due to the fact that in the nonoperative group the influence of physical functional disturbance was more marked than that of pain. In the study on the SF-36 summary score, the PCS score was significantly better in the osteotomy group than in the nonoperative group. This superior result, compared to the other groups, was ascribed to the fact that following osteotomy bone fusion occurs and bone metabolism normalizes, allowing the hip to function as living bone; thus, there is less anxiety about dislocation than in patients with THA. On the other hand, as assessed by the MCS score, the mental health of all three groups was similar to the Japanese population norm. This may be due to the fact that in chronic conditions such as NOFH many patients show a change in their perception of pain, and even in the presence of functional disturbance they are able to adjust to their new circumstances, thereby maintaining greater mental stability than might be expected. As a result, the fact that a significant difference was detected between the osteotomy and nonoperative groups on the physical function scale whereas no differences were found between the three groups in the SF-36 mental component score can be attributed to differ-
Fig. 3. SF-36 subscale scores distributed in age categories for nontraumatic osteonecrosis of the femoral head
ences in the activities of daily living (ADL) and degree of pain being reflected in the QOL score alone. The JOA score is employed as an objective evaluation method from the viewpoint of the physician, whereas the SF-36 is a health-related QOL survey based on the patient’s subjective experience. From the correlation coefficients of the two scores, the JOA score showed a significant correlation with mainly the physical health aspects of the SF-36 in each of the three groups but not with the mental health aspect (Table 3). These findings reflect the fact that with disease-specific evaluation and general health evaluations dissociations may be noted in the physical and mental aspects. Because relying on the JOA score alone does not permit evaluation of patients’ mental health, combined use of the SF-36 facilitates more detailed assessment of a patient’s total state. Regarding the choice of surgical method, Wiklund et al. described that THA, by mitigating pain and improving function, achieves a postoperative QOL similar to that of healthy persons.19 Nakai et al., in a survey of 37 patients with femoral head necrosis, concluded that, compared to osteotomy TRO, THA more reliably enhanced patient QOL9. However, in the present study, the SF-36 score of the osteotomy and THA groups did not differ significantly from that of the patients undergoing THA, with a stable QOL maintained. This may be explained by the fact that our hospital is an osteotomy center that has performed numerous such operations with stable results.11,20,21 If the indications for osteotomy are strictly adhered to and techniques carefully practiced, we believe that results as good as those of THA can be achieved. This study has several limitations. The first is that being a cross-sectional study a continuous evaluation could not be performed. Because we obtained QOL data from a survey conducted during a given period on a cross-sectional basis, the data of the osteotomy and
T. Seki et al.: QOL with femur head necrosis
THA groups are from the postoperative period, with differences noted in the length of the postoperative period in individual patients. However, no significant difference in the mean postoperative follow-up period was noted between the two groups in which these operations were conducted. On the other hand, evaluation of the mean follow-up period was considered to commence at the point after the initial presentation at which femoral head osteonecrosis was first diagnosed. It must be noted that accurately identifying the onset is difficult because femoral head osteonecrosis is asymptomatic in a considerable number of cases at the onset, and so many patients do not present to the hospital at this time. The second limitation is that because of the small number of NOFH cases we could not match for type and stage in each group. The third limitation is the fact that, with regard to the type of operation chosen, age and surgical conditions that influence the indications for osteotomy and THA differ. Therefore, it is difficult to compare clinical results. Finally, the nonoperative group included cases in which surgery was precluded because of the presence of co-morbidities or other reasons, which themselves may have decreased the QOL score. However, the fact that the postosteotomy QOL was assessed as being equivalent to that of THA may provide important information when making comparisons with patients undergoing conservative therapy or deciding on which surgical method to select. In future, long-term longitudinal studies addressing these issues are needed. Conclusions We grouped 81 patients with nontraumatic osteonecrosis of the femoral head into two surgical groups (femoral osteotomy or THA) and a nonoperative group and evaluated their health-related QOL using SF-36. In the nonoperative group, compared to the surgical groups, physical function impairment was a more potent factor than pain for decreasing QOL. Regarding the evaluation of the postoperative QOL score, osteotomy and THA give similar QOL results if the indication for osteotomy are strictly applied. References 1. Daniel M, Herman S, Dolinar D, Iglic A, Sochor M, Kralj-Iglic V. Contact stress in hips with osteonecrosis of the femoral head. Clin Orthop 2006;447:92–9.
121 2. Ficat RP. Idiopathic bone necrosis of the femoral head: early diagnosis and treatment. J Bone Joint Surg Br 1985;67:3–9. 3. Mont MA, Jones LC, Hungerford DS. Nontraumatic osteonecrosis of the femoral head: ten years later. J Bone Joint Surg Am 2006;88:1117–32. 4. Sugioka Y. Transtrochanteric anterior rotational osteotomy of the femoral head in the treatment of osteonecrosis affecting the hip: a new osteotomy operation. Clin Orthop 1978;130:191–201. 5. Shannon BD, Trousdale RT. Femoral osteotomies for avascular necrosis of the femoral head. Clin Orthop 2004;418:34–40. 6. Eskelinen A, Remes V, Helenius I, Pulkkinen P, Nevalainen J, Paavolainen P. Total hip arthroplasty for primary osteoarthrosis in younger patients in the Finnish arthroplasty register: 4,661 primary replacements followed for 0–22 years. Acta Orthop 2005;76:28–41. 7. Ito H, Matsuno T, Omizu N, Aoki Y, Minami A. Mid-term prognosis of non-traumatic osteonecrosis of the femoral head. J Bone Joint Surg Br 2003;85:796–801. 8. Jergesen HE, Khan AS. The natural history of untreated asymptomatic hips in patients who have non-traumatic osteonecrosis. J Bone Joint Surg Am 1997;79:359–63. 9. Nakai T, Masuhara K, Matsui M, Ohzono K, Ochi T. Therapeutic effect of transtrochanteric rotational osteotomy and hip arthroplasty on quality of life of patients with osteonecrosis. Arch Orthop Trauma Surg 2000;120:252–4. 10. Sugano N, Atsumi T, Ohzono K, Kubo T, Hotokebuchi T, Takaoka K. The 2001 revised criteria for diagnosis, classification, and staging of idiopathic osteonecrosis of the femoral head. J Orthop Sci 2002;7:601–5. 11. Sakano S, Hasegawa Y, Torii Y, Kawasaki M, Ishiguro N. Curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head. J Bone Joint Surg Br 2004;86:359–65. 12. Atsumi T, Kajiwara T, Hiranuma Y, Tamaoki S, Asakura Y. Posterior rotational osteotomy for nontraumatic osteonecrosis with extensive collapsed lesions in young patients. J Bone Joint Surg Am 2006;88(suppl. 3):42–7. 13. Fukuhara S, Bito S, Green J, Hsiao A, Kurokawa K. Translation, adaptation, and validation of the SF-36 Health Survey for use in Japan. J Clin Epidemiol 1998;51:1037–44. 14. Takeda H, Kamogawa J, Sakayama K, Kamada K, Tanaka S, Yamamoto H. Evaluation of clinical prognosis and activities of daily living using functional independence measure in patients with hip fractures. J Orthop Sci 2006;11:584–91. 15. Ware JE, Kosinski M. Interpreting SF-36 summary health measures: a response. Qual Life Res 2001;10:405–13. 16. Beaule PE, Dorey FJ, Hoke R, Leduff M, Amstutz HC. The value of patient activity level in the outcome of total hip arthroplasty. J Arthroplasty 2006;21:547–52. 17. Wood GC, McLauchlan GJ. Outcome assessment in the elderly after total hip arthroplasty. J Arthroplasty 2006;21:398–404. 18. Kawasaki M, Hasegawa Y, Sakano S, Torii Y, Warashina H. Quality of life after several treatments for osteoarthritis of the hip. J Orthop Sci 2003;8:32–5. 19. Wiklund I, Romanus B. A comparison of quality of life before and after arthroplasty in patients who had arthrosis of the hip joint. J Bone Joint Surg Am 1991;73:765–9. 20. Hasegawa Y, Sakano S, Iwase T, Iwasada S, Torii S, Iwata H. Pedicle bone grafting versus transtrochanteric rotational osteotomy for avascular necrosis of the femoral head. J Bone Joint Surg Br 2003;85:191–8. 21. Iwasada S, Hasegawa Y, Iwase T, Kitamura S, Iwata H. Transtrochanteric rotational osteotomy for osteonecrosis of the femoral head: 43 patients followed for at least 3 years. Arch Orthop Trauma Surg 1997;116:447–53.