Search Results
The initial search returned 1438 potentially relevant articles from the 3 databases. Four hundred and four duplicates were deleted, leaving 1034 articles for screening. Nine hundred and eighty three irrelevant citations were excluded after screening titles and abstracts by both reviewers, and 51 full-text papers remained for review. Another 41 studies were rejected for several reasons, such as other surgical methods (n = 17), lack of raw date (n = 6), short follow-up (n = 9), duplicate research (n = 3), commentary, case reports or review (n = 5), inaccessible language (n = 1). Finally, 10 references were included in this study [16–18, 24–30]. The details of study selection process can be found in the Fig. 1.
Study Characteristics And Quality
Nine retrospective case-series studies and one retrospective case-control study, including 3042 patients (3481 hips), were finally selected [16–18, 24–30]. All studies were single center [16, 17, 24–30] except one multicenter study [18]. The main features of the included studies are shown in Table 1 and Table 2.
Table 1
Characteristics of the included studies
Author/ Year/ Country | Study Design | Average age(years) | Gender M/F | Number of patients/hips (follow-up) | Classifications system | Stage | Etiology (hips) | Follow-up time(year) | Validity of the studies |
Eisenschen/2001/ Germany | retrospective case series | NM | 81/21 | 90/90 | ARCO | NV | trauma(22)/alcohol(20)/steroids (12)/ idiopathic(16)/sickle cell anemia(1). | 5 (0.5–10) | H |
Xie/ 2019/ China | retrospective case series | 38.01 ± 9.43 | 575/281 | 856 /1006 | Ficat and Arlet | II(575)/ III(382)/IV(49) | steroid(382)/alcohol abuse(378)/traumatic (159)/idiopathic(87) | 15(5–25) | M |
Hasegawa/ 2003/ Japan | retrospective case-control | 37.9 (25–53) | 23/3 | 26/31 | * | II(28)/III-A(3) and I-B(1)/I-C(25)/II(4)/ II1-B(1) | alcohol(16)/steroid(8)/idiopathic(7) | 13 (10–15) | 8(NOS) |
Zhao/2017/ China | retrospective multicenter case series | 43.15 ± 9.14 | 1364/826 | 1912/2179 | Ficat and Arlet | II(1733)/III(776)/IV(181) | Alcoholic(747)/steroid(497)/idiopathic(226)/traumatic(720) | 12 (5–25) | M |
Ishizaka/ 1997/ Japan | retrospective case series | 33(15–66) | 16/8 | 24/31 | Ficat and Arlet | II(18)/III(13). | steroid(17)/alcohol(10)/idiopathic(4) | 6 (2–11) | H |
Leung/1996/ China | retrospective case series | 32(24–52) | 12/6 | 18/21 | Myer's classification | III(6) /IV(8)/V(7) | idiopathic(8)/alcoholic(3)/steroidal(7)/ posttraumatic(3) | (5–12) | H |
Babhulkar/2009/India | retrospective case series | 32(18–52) | 26/5 | 31/31 | ARCO | IIB(9)/ IIIC(22) | alcohol (16)/ corticosteroid(12)/idiopathic(3) | 8(5–8) | M |
Chen/2009/China | retrospective case series | 37(23–64) | 31/1 | 32/33 | ARCO | IIIA(26)/IIIB(7) | alcohol(27)/idiopathic(5)/ steroid(1) | 5.8(0.7-l3.8) | M |
Pavlovcic/ 1999/ Slovenia | retrospective case series | 38(25–55) | 23/1 | 24/24 | Ficat | II(7) /III(17) | idiopathic(12)/alcohol abuse(8)/traumatic(2)/ steroid use(2). | 12.2(9–14) | H |
Nagoya/ 2004/Japan | retrospective case series | 35(17–62) | 20/9 | 29/35 | ARCO | II(28) /III(7) | steroid(14)/ alcohol(10)/idiopathic(5) | 8.6 (3–17) | M |
ARCO, Association Research Circulation Osseous; M, moderate risk; H, high risk; NM, not mention; NV, not available; *modified Inoue and Ono classification and the Japanese Investigation Committee; NOS, Newcastle-Ottawa Scale |
Table 2
The intervention characteristics of the studies
Author/ Year | Kinds of pedicle bone flap/Size(cm) | Duration of the operation | Postoperative management | defined clinical failure |
Eisenschen/ 2001 | vascular pedicled iliac crest with DICA /6 × 2 | NM | Nonweight bearing for 6 months | NM |
Xie/ 2019 | vascular iliac bone grafting with ALCA/5 × 3 | 65(55–100) minutes | Non-weight bearing in the first 6 weeks, full weight bearing 6 months postoperatively | Conversion to THA or any other hip-preserving surgery |
Hasegawa/ 2003 | vascular iliac pedicle bone graft with SICA (n = 23) or DICA (n = 8)/5 × 1.5 | NM | Ambulation was not permitted in first 3 weeks, partial weight-bearing from 12 weeks, full weight-bearing from 24 weeks | An clinical score of less than 70 points or conversion to THA |
Zhao/ 2017 | one-sided cortical pedilced iliac bone flap with ALCA /2.5 × 2.5 | NM | Nonweight bearing in the first 6 weeks, full weight bearing 6 months postoperatively | Conversion to THA or any other hip-preserving surgery |
Ishizaka/ 1997 | tricortical vascularized pedicle iliac bone block with DICA /2 × 2 × 5 | 2.5 hours | Nonweight bearing for 6 months, partial weight bearing for the next 6 months | Progressive collapse of 2 mm or more, or with osteoarthritic changes. |
Leung, P/1996 | a iliac crest bone with DICA /NM | NM | Bed rest for 3–4 weeks, nonweight-bearing walking at the 4 week, weight-bearing until 8 weeks | Converted to THA |
Babhulkar/2009 | part of iliac crest with DICA/NM | NM | The patients were mobilized after 15 days in bed, and after 4–6 weeks, patients were mobilized out of bed on non-weight bearing | NM |
Chen/2009 | a tricortical vascularized iliac bone block with DICA /1.5 × 5 | NM | Toe-touch weight-bearing for the first 6 weeks, then progressive weight-bearing was permitted, full weight-bearing after 6 months | Conversion to TKA and radiographic failure as progressive femoral head collapse or secondary osteoarthritis |
Pavlovcic/1999 | a vascularized iliac crest bone graft with DICA /2 × 5 | NM | Passive hip movement started 3 to 4 days, full weight bearing 6 months later | Collapse of the femoral head within 3 years postoperatively |
Nagoya/2004 | vascularized iliac bone graft perfused by DICA /NM | NM | Bed rest for 2 weeks, partial weight bearing for the next 6 months | Collapse occurred or progressed |
NM, not mentioned; DICA, deep iliac circumflex artery; ALCA, ascending branch of the lateral circumflex artery; SICA, superficial iliac circumflex artery; HHS, Harris Hip Score; THA, total hip arthroplasty |
Nine case series studied had moderate to high risks of bias according to IHE [16–18, 24, 25, 27–30], while the case-control study obtained 8 scores based on NOS [26]. The validities of included studies are summarized in Appendix 2 and Appendix 3.
Nutrient Vessels Of The Bone Flap
The nutrient vessels of the iliac bone flap used by eligible studies contained DICA, ALCA and SICA. Seven studies used DICA [16, 24, 25, 27–30], two studies used ALCA [17, 18], and the remaining one used DICA or SICA [26]. Two studies reported the average length of operation, in which one took 65(55–100) minutes with ALCA bone grafting [17], and the other spent about 2.5 hours with DICA bone grafting [29]. The remaining studies did not mention it.
Fixation Of The Bone Flap
Only 5 studies provided information about the fixation of bone grafts [16, 25, 28–30]. The bone block was secured by an additional screw [25] or by taking the stitch through the hole prepared by drilling in the neck and graft [16], while additional fixation was not applied in the remaining studies [28–30].
Clinical Evaluation
Clinical outcomes were evaluated by the following methods: Harris hip score (HHS) [16–18, 24, 26, 27], Japan Orthopaedic association hip (JOA) score [25], Merled’ Aubigne and Postel score (MP score) [29], and Charnley’s scoring system [30].
Postoperative Management
As shown in Table 2, all studies elaborated on postoperative management. Patients were generally recommended to begin toe-touch weight-bearing in the first 6 weeks after surgery, maintain partial weight-bearing for the next 6 weeks, and start complete weight-bearing after 3 to 6 months.
Definitions Of Clinical Failure
Various studies followed different definitions of clinical failure. Seven studies considered “conversion to THA or any other hip-preserving surgery” or “collapse of the femoral head and poor clinical function of the hip” as end points [17, 18, 24, 26, 28–30]. One study defined “femoral head collapse or progress of ONFH” as a failure [25]. And the remaining two studies did not give specific definitions [16, 27].
Clinical Outcomes
The average age of included patients was approximately 41.2 (15–66) years (excluding the study by Eisenschen [27]), and the male took up approximately 71.4%. The etiology mainly comprised alcohol abuse (35.5%), steroid use (27.3%), trauma (26.0%), Idiopathic (10.7%), and other (0.5%). The severity of ONFH was classified by different grading systems. Four studies used the Ficat classification [17, 18, 28, 29]. Four studies used the Association Research Circulation Osseous (ARCO) classification [16, 24, 25, 27]. And the remaining 2 studies used Myer’s classification [30], Inoue and Ono classification as well as Japanese Investigation Committee ( JIC ) classification [26], respectively. The maximum average follow-up period was 15 (5–25) years [17], and the minimum average period was 5 (0.5–10) years [27].
Success Rate Of Hip-preserving Surgery With VPIBG
The random-effects model was used because of the heterogeneity(I2 = 67.3%, P = 0.003). A total of 3413 hips in 8 studies were pooled into the meta-analysis of clinical success rates [16–18, 26–30], which showed that the overall ES was 0.89 (95% CI, 0.86–0.92), and the ES in subgroup analysis were 0.88 (95% CI, 0.78–0.98) and 0.90 (95% CI, 0.87–0.92) at an average follow-up of 5–10 years and 10–15 years, respectively, as shown in Fig. 2. Funnel plots illustrating the meta-analysis of clinical success rates indicated no obvious publication bias (Fig. 3).
The remaining 2 studies [24, 25] were not suitable for merger because of different inclusion criteria [24] or definition of clinical failure [25], and therefore were given a descriptive analysis. One study reported a success rate of 24.20% [24], which might be associated with all the included subjects who were ONFH patients with segmental collapse, because the well defined indications for this operation were those with precollapsed or early collapsed stage [5, 31]. The other study reported a success rate of 45.70%, which might be related to the study’s definition of failure as “femoral head collapse or progress of ONFH” [25]. This was because a proportion of patients, who showed radiographic progression after hip-preserving surgery and whose HHS improved significantly, did not need to receive THA subsequently [32]. Therefore, these patients should not be considered clinical failures. Given all the above reasons, data of these 2 studies were not merged in the meta analysis. Clinical outcomes of each studies are shown in the Table 3.
Table 3
The outcomes of the studies
Author/ Year | Score system | Score (M ± SD) | outcomes | Clinical success rate | Complications/(rate%) | lost follow-up |
preoperative | postoperative |
Eisenschen/ 2001 | HHS | NM | 89 | conversion to THA(8 ) within 5 years, good or excellent(71) | 78.90% | 2 deep thrombosis of the femoral vein, 7 paresthesia and pain at the donor defect, 5 abdominal weakness, and 2 secondary wound healing/16 (17.7%) | died (5)/moved abroad(2)/lost followup(5) |
Xie/ 2019 | HHS | 66.42 ± 6.52 | 87.43 ± 6.42 | 105 hips were converted to THA | 89.60% | 23 deep venous thrombosis, 16 meralgia paresthetica (which resolved), 47 secondary wound healing/86 (8.5%) | 75 patients (101hip) lost to follow-up, including 25 patients (32 hips) who died |
Hasegawa/ 2003 | HHS | 69 ± 9 | 83 ± 8 | conversion to THA( 2 ), 1 within 1 year and another at 9 years after surgery | 90.30% | 3 surgical wound necrosis, 8 irritation of the lateral femoral cutaneous nerve/11(35.5%) | 1 died at 8 years after operation, and 1was unable to walk due to cerebrovascular attack 7 Years after operation |
Zhao/ 2017 | HHS | 66.54 ± 6.05 | 83.63 ± 5.03 | converted to THA(215), including stage II (19 ), stage III (162 ), stage IV (34). no radiographic osteonecrotic progress(1787) | 90.13% | 25 deep venous thromboses, 16 sensory deficits, 40 superficial infection and hematoma, 47 wound dehiscence/128 (5.9%) | NO |
Ishizaka/ 1997 | MP | 13.5 | 15.7 | revised operations(3), satisfactory(24) | 77.4% | NM | NM |
Leung, P/1996 | Charnley | NA | NA | converted to THA(1), heaviness and weakness in the involved hips(7) at 2 years after operative afrer prolonged walking | 95.20% | NM | NO |
Babhulkar/2009 | HHS | 52.52 ± 5.08 | 80.71 ± 6.70 | 1 from stage III converted to THA | 96.80% | 1 superficial infection/1(3.2%) | NO |
Chen/2009 | HHS | 62a | 80a | converted to TKA(25), mean survival time of the preserving-hip was 74 (44–95) months | 24.20% | NM | 3 lost to follow-up, and 2 died |
Pavlovcic/ 1999 | NA | NA | NA | poor results(8), fair results(6), hips good results(5), excellent results(5) | 66.70% | 3 skin necrosis/3(12.5%) | NO |
Nagoya/ 2004 | JOA | 50.9b/49.8c | 58.1b/79.2c | 19 hips collapse, 16 hips no collapse.16 of 28 stage 2 hips not collapse, in all 7 stage 3 hips collapse | 45.70% | 10 numbness of the lateral thigh or paresthesia around the operation wound. Phantom pain occurred on the iliac bony eminence/10(28.6%) | NO |
M, mean difference; SD, standard deviation; HHS, Harris hip score; NM, not mentioned; NA, not available; JOA, Japanese Orthopaedic Association score; MP, Merled' Aubigne and Postel score; a The score for the 8 hips that were preserved by the surgery(not containing 25 hips that convert to TKA); b the mean score for the hips that subsequently collapsed; c the mean score for the hips without collapse |
Rate Of Conversion To THA
Pooled analysis of THA conversion rates derived from 7 studies (3389 hips) showed the overall ES of 0.10 (95% CI, 0.09–0.11) with the fixed-effects model (I2 = 8.5%, P = 0.364) [16–18, 26, 27, 29, 30], and showed the ES of 0.06 (95% CI, 0.03–0.10) and 0.10 (95% CI, 0.09–0.11) at an average follow-up of 5–10 years and 10–15 years in subgroup analysis, respectively (Fig. 4).
Viability Evaluation Of Implanted Flap
Viability evaluation of implanted flap was performed in 2 studies [16, 24]. One study showed that 9 patients underwent digital subtraction arteriography at the end of 12 weeks and all cases proved the patency of DICA. The study also showed that the grafted areas of the femoral heads were showed high uptake through bone scan in 6 other patients [16]. Another study evaluated 17 hips through postoperative magnetic resonance imaging (MRI) scans and found isointense signals relative to the normal marrow and gadolinium enhancement in the viable graft [24].
Complications
Seven studies reported 255 complications [16–18, 25–28], with rates ranging from 3.2% (1/31 hips) [16] to 35.5% (11/31 hips) [26]. The pooled analysis of complication rates derived from these 7 studies (3396 hips) showed the overall ES of 0.12 (95% CI, 0.08–0.18) with the random-effects model (I2 = 88.1%, P = 0.00), as shown in Fig. 5. The three most common complications were secondary wound healing (37.6%), numbness or paresthesia of the lateral thigh (22.4%), and deep venous thromboses (19.6%).