Aims. Osteonecrosis (ON) can cause considerable morbidity in young people who undergo treatment for acute lymphoblastic leukaemia (ALL). The aims of this study were to determine the operations undertaken for ON in this population in the UK, along with the timing of these operations and any sequential procedures that are used in different joints. We also explored the outcomes of those patients treated by core decompression (CD), and compared this with conservative management, in both the pre- or post-collapse stages of ON. Methods. UK treatment centres were contacted to obtain details regarding surgical interventions and long-term outcomes for patients who were treated for ALL and who developed ON in UKALL 2003 (the national leukaemia study which recruited patients aged 1 to 24 years at diagnosis of ALL between 2003 and 2011). Imaging of patients with ON affecting the femoral head was requested and was used to score all lesions, with subsequent imaging used to determine the final grade. Kaplan-Meier failure time plots were used to compare the use of CD with non surgical management. Results. Detailed information was received for 85 patients who had developed ON during the course of their ALL treatment. A total of 206 joints were affected by ON. Of all joints affected by ON, 21% required arthroplasty, and 43% of all hips affected went on to be replaced. CD was performed in 30% of hips affected by ON. The majority of the hips were grade 4 or 5 at initial diagnosis of ON. There was no significant difference in time to joint collapse between those joints in which CD was performed, compared with no joint-preserving surgical intervention. Conclusion. There is a high incidence of surgery in young people who have received treatment for ALL and who have developed ON. Our results suggest that CD of the femoral head in this group of patients does not delay or improve the rates of femoral head survival. Cite this article: Bone Joint J 2021;103-B(3):589–596

Bertolotti’s syndrome, first described in 1917, is characterised by the presence of an anomaly of unilateral or bilateral enlargement of the transverse process of the most caudal vertebra that may articulate or fuse with the sacrum or ilium. This gives rise to low back pain. Although described, relevant literature is sparse and in particular, no evidence exists as to its incidence specifically in young people. This study analysed all MRI scans of the lumbosacral spine performed on patients between July 2003 and November 2004 inclusive. MRI scans for all indications were included in the study. Out of a total of 818 MRI scans of the lumbosacral spine, 627 showed disc disease. Of these, 35 had radiological signs of Bertolotti’s syndrome (7 bilateral, 28 unilateral). There were 22 males and 17 females in this group. The average age of the Bertolotti group was 31.8+/−12.0 years (range: 15–60). This was less than those with multiple disc disease whose average age was 44.0+/−15.6 years (p< 0.0002, ANOVA), those with isolated disc disease (41.1+/−16.0 years, p=0.013, ANOVA) and those with isolated disc disease at the L4/5 level (46.0+/−11.3 years, p=0.003, ANOVA). The overall incidence of Bertolotti’s syndrome in this study was 5.6%. However, 18 of the patients in the Bertolotti group were under 30 years of age giving an overall incidence in this age group of 8.9%. Bertolotti’s syndrome is a frequently occurring pathology in the lumbosacral spine. It occurs in significantly younger patients than either multi-level disc disease or isolated disc disease including at the L4/5 level. In the under 30 group its incidence of 8.9% mandates that it must form part of a differential list in the investigation of low back pain in young people

Aims. The Bracing Adolescent Idiopathic Scoliosis (BASIS) study is a randomized controlled non-inferiority pragmatic trial of ‘full-time bracing’ (FTB) compared to ‘night-time bracing’ (NTB) for the treatment of adolescent idiopathic scoliosis (AIS). We anticipated that recruiting patients to BASIS would be challenging, as it is a paediatric trial comparing two markedly different bracing pathways. No previous studies have compared the experiences of AIS patients treated with FTB to those treated with NTB. This qualitative study was embedded in BASIS to explore families’ perspectives of BASIS, to inform trial communication, and to identify strategies to support patients treated in a brace. Methods. Semi-structured interviews were conducted with parents (n = 26) and young people (n = 21) who had been invited to participate in BASIS at ten of the 22 UK paediatric spine services in hospitals recruiting to BASIS. Audio-recorded interviews were transcribed and analyzed thematically. Results. Families viewed their interactions with BASIS recruiters positively, but were often confused about core aspects of BASIS, such as the aims, expectations of bracing, and the process of randomization. Participants typically expressed a preference for NTB, but recruiters may have framed NTB more favourably. Patients and parents reported challenges wearing a brace, such as physical discomfort, feelings of self-consciousness, difficulty participating in physical activities, and strain on financial resources to support brace use. Patients in FTB reported more pronounced challenges. While families valued health professional support, they felt there was a lack of social, emotional, and school support, and relied on online resources, as well private counselling services to address this need. Conclusion. The findings informed the development of resources and strategies, including guidance for schools and the recommendations in this paper, to support patients to wear NTB and FTB as prescribed. The results indicated opportunities for recruiters to enhance trial communication in ways that could improve informed consent and recruitment to BASIS, and inform future trials of bracing. Cite this article: Bone Jt Open 2025;6(2):135–146

Between 1997 and 2000, internal arthrodiastasis procedures (endo-apparatus), using an internal skeletal distraction device, were performed on 33 young patients who had reached the point of total hip arthroplasty or arthrodesis.

The mean age of the 20 males and 13 females was 19 years (range 11 to 51 years). We removed 19 implants, eight after completion of treatment or because they had outlived their usefulness, and 11 because no improvement in the hip disorder had been achieved.

Good results were achieved in two thirds of the patients, including patients suffering from avascular necrosis of the femoral head, old Perthes’ disease and contained hip dysplasia with joint space narrowing and pain. Chondrolysis and stiffness of the hip appear to be contraindications for this type of treatment. The three post-traumatic hip disorders were probably also not ideal cases.

In young patients, the results of total hip arthroplasty after trauma are poor, and the indications for internal arthrodiastasis should be redefined.

Background:

Long-Term Follow-Up Of Lung Function And Quality Of Life (Qol) In Those Undergoing Combined Anterior And Posterior Spinal Fusion (A/Psf) For Ais Is Not Well Documented With Only One Study Extending Beyond 2 Years.

Introduction: Stress fracture of the femoral head is a rare condition and usually occurs in people with poor bone quality as an insufficiency fracture. We evaluated the clinical aspects of subchondral fatigue fractures of the femoral head (SFFFH) that occurred in young healthy people. Materials and Methods: Between January 1998 and November 2001, 7 cases of SFFFH in 5 patients were treated. The characteristics of this condition were ascertained by assessing the clinical course and findings of radiographs, bone scintigrams, and magnetic resonance (MR) images. Results: All patients were male military recruits in their early twenties. Pain developed within 6 months after recruitment. On initial radiographs, definite abnormal findings were observed in 3 hips of 2 patients. In 2 of them, the femoral head was markedly collapsed. In the other 4 hips, no definite abnormal findings were noticed. The bone scintigrams showed increased radionuclide uptake in the femoral head. MR images demonstrated localized abnormal signal intensity areas (bone marrow edema pattern) in the femoral head. In all cases, MR crescent signs were observed. In the cases without collapse of the femoral head, the pain decreased gradually and disappeared completely in 6 months with improving findings on follow-up MR images. The collapsed cases needed surgical treatment: total hip arthroplasty or strut iliac bone grafting. Discussion: When a military recruit or an athlete is complaining of hip pain, a high index of suspicion for SFFFH is necessary to prevent the collapse of the femoral head. Bone scintigrams are of great value as a screening tool. Osteonecrosis of the femoral head can be differentiated by the findings on MR images

Aims. The aim of this study was to explore parents and young people’s experience of having a medial epicondyle fracture, and their thoughts about the uncertainty regarding the optimal treatment. Methods. Families were identified after being invited to participate in a randomized controlled trial of surgery or no surgery for displaced medial epicondyle fractures of the humerus in children. A purposeful sample of 25 parents (22 females) and five young people (three females, mean age 11 years (7 to 14)) from 15 UK hospitals were interviewed a mean of 39 days (14 to 78) from injury. Qualitative interviews were informed by phenomenology and themes identified to convey participants’ experience. Results. The results identify parents’ desire to do the best for their child expressed through two themes: 1) ‘uncertainty’ (being uncertain about the best treatment option); and 2) ‘facilitating recovery’ (sharing the experience). Parents and young people were shocked when confronted with uncertainty about treatment and they felt responsible for the decision. They searched for further information, drew on their own experience, and struggled to weigh up risks of the treatments. Discussion with surgeons provided crucial support for decision-making, and young people were involved to a varying degree. In facilitating recovery, parents balanced increasing activity with protecting their child, but lacked knowledge about pain management, and how to improve strength and function of the arm. They hoped for a return to normal, including competitive sports. Conclusion. Surgeons are aware of the impact of injury on children and their parents; however, they may be less aware of the turmoil created by treatment uncertainty. Confident surgeons who appreciate and contextualize the importance of pre-existing experience and beliefs are best placed to help the family develop confidence to embrace uncertainty, particularly regarding participation in clinical trials. Cite this article: Bone Jt Open 2021;2(6):359–364

Primary malignant bone and soft tissue tumours often occur in the lower extremities of active individuals including children, teenagers and young adults. Survivors routinely face long-term physical disability. Participation in sports is particularly important for active young people but the impact of sarcoma treatment is not widely recognised and clinicians may be unable to provide objective advice about returning to sports. We aimed to identify and summarise the current evidence for involvement in sports following treatment of lower limb primary malignant bone and soft tissue tumours. A comprehensive search strategy was used to identify relevant studies combining the main concepts of interest: (1) Bone/Soft Tissue Tumour, (2) Lower Limb, (3) Surgical Interventions and (4) Sports. Studies were selected according to eligibility criteria with the consensus of three authors. Customised data extraction and quality assessment tools were used. 22 studies were selected, published between 1985 – 2020, and comprising 1005 patients. Fifteen studies with data on return to sports including 705 participants of which 412 (58.4%) returned to some form of sport at a mean follow-up period of 7.6 years. Four studies directly compared limb sparing and amputation; none of these were able to identify a difference in sports participation or ability. Return to sports is important for patients treated for musculoskeletal tumours, however, there is insufficient published research to provide good information and support for patients. Future prospective studies are needed to collect better pre and post-treatment data at multiple time intervals and validated clinical and patient sports participation outcomes such as type of sports participation, level and frequency and a validated sports specific outcome score, such as UCLA assessment. In particular, more comparison between limb sparing and amputation would be welcome

Aims. We performed a systematic literature review to define features of patients, treatment, and biological behaviour of multicentric giant cell tumour (GCT) of bone. Methods. The search terms used in combination were “multicentric”, “giant cell tumour”, and “bone”. Exclusion criteria were: reports lacking data, with only an abstract; papers not reporting data on multicentric GCT; and papers on multicentric GCT associated with other diseases. Additionally, we report three patients treated under our care. Results. A total of 52 papers reporting on 104 patients were included in the analysis, with our addition of three patients. Multicentric GCT affected predominantly young people at a mean age of 22 years (10 to 62), manifesting commonly as metachronous tumours. The mean interval between the first and subsequent lesions was seven years (six months to 27 years). Synchronous lesions were observed in one-third of the patients. Surgery was curettage in 63% of cases (163 lesions); resections or amputation were less frequent. Systemic treatments were used in 10% (n = 14) of patients. Local recurrence and distant metastases were common. Conclusion. Multicentric GCT is rare, biologically aggressive, and its course is unpredictable. Patients with GCT should be followed indefinitely, and referred promptly if new symptoms, particularly pain, emerge. Denosumab can have an important role in the treatment. Cite this article: Bone Joint J 2022;104-B(12):1352–1361

It is known that the gait dynamics of elderly substantially differs from that of young people. However, it has not been well studied how this age-related gait dynamics affects the knee biomechanics, e.g., cartilage mechanical response. In this study, we investigated how aging affects knee biomechanics in a female population using subject-specific computational models. Two female subjects (ages of 23 and 69) with no musculoskeletal disorders were recruited. Korea National Institute for Bioethics Policy Review Board approved the study. Participants walked at a self-selected speed (SWS), 110% of SWS, and 120% of SWS on 10 m flat ground. Three-dimensional marker trajectories and ground reaction forces (Motion Analysis, USA), and lower limbs’ muscle activities were measured (EMG, Noraxon USA). Knee cartilage and menisci geometries were obtained from subjects’ magnetic resonance images (3T, GE Health Care). An EMG-assisted musculoskeletal finite element modeling workflow was used to estimate knee cartilage tissue mechanics in walking trials. Knee cartilage and menisci were modeled using a transversely isotropic poroviscoelastic material model. Walking speed in SWS, 110%, and 120% of SWS were 1.38 m/s, 1.51 m/s, and 1.65 m/s for the young, and 1.21 m/s, 1.34 m/s and 1.46 m/s for the elderly, respectively. The maximum tensile stress in the elderly tibial cartilage was ~25%, ~33%, and ~32% lower than the young at SWS, 110%, and 120% of SWS, respectively. These preliminary results suggest that the cartilage in the elderly may not have enough stimulation even at 20% increases in walking speed, which may be one reason for tissue degeneration. To enhance these findings, further study with more subjects and different genders will investigate how age-related gait dynamics affects knee biomechanics. Acknowledgments: Australian NHMRC Ideas Grant (APP2001734), KITECH (JE220006)

Cancer is a major health problem for teenagers and young adults (TYA’s). However, many young people are often late to receive a cancer diagnosis. Young people may not recognize symptoms as serious and delay seeking help. Furthermore, there is evidence to suggest that once a young person does seek help from a general practitioner (GP), significant delay can still occur. During the annual Find Your Sense of Tumour (FYSOT) conference 2007; a group of 200 TYA’s with cancer participated in a survey regarding their diagnostic experience; the cohort included 22 patients with bone tumours. Following the onset of symptoms; nearly half of the TYA’s with a bone tumour (46%) reported 4 or more visits to their G.P before being referred to a specialist. However, 91% of bone tumour patients had multiple, ‘classic’ cancer symptoms and the majority (77%) sought help from the G.P within 4 weeks of noticing symptoms. The ‘Christie Crew’ (CC) are a group of TYA’s who have been treated for cancer and work on various projects to improve cancer services. The Christie Crew wanted to empower young people with the knowledge that TYA’s do get cancer and to raise awareness of the signs and symptoms of cancer and have produced a DVD and education pack that has been launched across 80 schools and throughout the North West. The DVD is highlights individual’s stories of diagnosis. There is also a poster campaign highlighting signs and symptoms of cancer being displayed in large public venues across the Manchester area. The aim is to roll out the project nationally as part of the health awareness (Healthy Schools) initiative. By highlighting that young people get cancer it is hoped that more young people will recognise the signs and symptoms and be empowered to go to their GP if they have persistent problems

Purpose. Factors contributing to chronic postoperative pain (CPOP) are poorly defined in young people and developmental considerations are poorly understood. With over 5 million children undergoing surgery yearly and 25% of adults referred to chronic pain clinics identifying surgery as the antecedent, there is a need to elucidate factors that contribute to CPOP in young people. The present study includes patients undergoing hip preservation surgery at a children's hospital. Methods. The HOOS and the SF-12 Health Survey were administered to 614 patients prior to surgery with 422 patients completing follow-up data (6-months, 1-year, and 2-years post-surgery). Examining baseline characteristics for those who completed follow-up versus those who did not, the only significant difference was that patients with more than one surgery were less likely to complete follow-up measures. Pain, quality of life, and functioning across time were examined using SAS PROC TRAJ procedure, a mixture model that estimates a regression model for each discrete group within the population. Longitudinal pain trajectories were empirically grouped. Baseline preoperative characteristics of age, gender, preoperative pain, quality of life, functioning, and mental health that could potentially distinguish trajectory groups were examined. Results. A three trajectory model (low pain, pain improvement, and high pain) emerged indicating three different treatment responders. Pain trajectory groups did not differ significantly on gender, presurgical age, BMI, prior hip surgery, surgical type, joint congruence, or Tönnis grade. The pain trajectory groups differed significantly from each other on presurgical pain, pain chronicity, quality of life, and functioning. Those in the high pain group and pain improvement group endorsed having presurgical depression at significantly higher rates and lower presurgical quality of life compared to those in the low pain group (p<.01). Similarly, those in the high pain group reported significantly worse functioning prior to surgery compared to the pain improvement group (p<.0001) and those in the low pain group (p<.0001). Conclusions. Chronic pain is a common problem and surgery can be a trigger. There may be a subset of hip preservation surgery patients who are predisposed to chronic pain independent of hip health. The results demonstrate the need for preoperative screening prior to hip preservation surgery. A prospective, interventional study to identify patients at risk for a poor pain trajectory is underway. Significance. This is the largest study to date to examine longitudinal pain, quality of life, and functioning trajectories for adolescent and young adults undergoing hip preservation surgery. Chronic pain is a serious public health concern, with the United States spending $19 billion annually on pain-related disability. Identifying predictors of poor long-term outcomes in adolescents and young adult samples with postoperative pain may prevent the development of chronic pain into adulthood as well as inform presurgical preparation and postsurgical care

Introduction. The ankle cartilage has an important function in walking movements, mainly in sports; for active young people, between 20 and 30 years old, the incidence of osteochondral lesions is more frequent. They are also more frequent in men, affecting around 21,000 patients per year in USA with 6.5% of ankle injuries generating osteochondral lesions. The lesion is a result of ankle sprain and is most frequently found in the medial location, in 53% of cases. The main objective of this work was to develop an experimental and finite element models to study the effect of the ankle osteochondral lesion on the cartilage behavior. Materials and Methods. The right ankle joint was reconstructed from an axial CT scan presenting an osteochondral lesion in the medial position with 8mm diameter in size. An experimental model was developed, to analyze the strains and influence of lesion size and location similar to the patient. The experimental model includes two cartilages constructed by Polyjet™ 3D printing from rubber material (young modulus similar to cartilage) and bone structures from a rigid polymer. The cartilage was instrumented with two rosettes in the medial and lateral regions, near the osteochondral region. The fluid considered was water at room temperature and the experimental test was run at 1mm/s. The Finite element model (FE) includes all the components considered in the experimental apparatus and was assigned the material properties of bone as isotropic and linear elastic materials; and the cartilage the same properties of rubber material. The fluid was simulated as hyper-elastic one with a Mooney-Rivlin behavior, with constants c1=0.07506 and c2=0.00834MPa. The load applied was 680N in three positions, 15º extension, neutral and 10º flexion. Results. The experimental strain measured in the cartilage in the rosettes presents similar behavior in all experiments and repetitions. The maximum value observed near the osteochondral lesion was 3014(±5.6)µε in comparison with the intact condition it was 468 (±1.95)µε. The osteochondral lesion increases the strains around 6.5 times and the synovial liquid reduces the intensity of strain distribution. The numerical model presents a good correlation with the experiments (R2 0.944), but the FE model underestimates the values. Discussion and conclusion. As a first conclusion, the size of the osteochondral lesion is important for the strains developed in cartilage. The size of lesion greater than 10mm is critical for the strains concentration. The synovial fluid present an important aspect in the strains measured, it reduces the strains in the external surface of cartilage and induces an increase in the lower part. This phenomenon should be addressed in more studies to evaluate this effect

Background: Guidelines for the management of Low Back Pain (LBP) consistently recommend that initial assessment should focus on the detection of serious spinal pathologies. In 1994 the UK Clinical Standards Advisory Group introduced the concept of “red flags”. One flag is the presentation of back pain in people under the age of 20. LBP in children is common, with an annual and lifetime prevalence of around 30%. Because many cases of benign and malignant spinal tumours and spinal infection have been documented in this age group, young people with LBP who are referred to secondary care are investigated by MRI. Purpose: The purpose of this study is to review the incidence of tumour and infection in subjects under age 20, who present to secondary care with LBP, but do not have concerning objective findings such as neurology, fever, acute deformity or scoliosis. Method/Results: A retrospective analysis of the MRI database, at a specialist orthopaedic hospital, from 1994 until 2005 identified 403 limited MRI’s taken in LBP patients under the age of 20. Analysis revealed 2 radiological reports of spinal tumour, 1 ependymoma and 1 osteoid osteoma and no cases of spinal infection. Histology confirmed pathology in the ependymoma but excluded serious pathology in the osteoid oste-oma. Other MRI findings, included minor degenerative change (17%), pars defect (9%) and disc prolapse (4%). Therefore, over an 11 year period only 0.25% of young people with LBP who underwent limited MRI were found to have serious pathology. Conclusion: In conclusion, LBP is relatively common in people under the age of 20 and can be severe enough to warrant secondary care referral. However, in the absence of other objective findings, serious pathologies such as cancer and infection remain rare. These results support the use of limited MRI for screening. However, further research into the clinical value of “under 20” as an independent red flag is recommended

Bertolotti’s syndrome is characterised by anomalous enlargement of the transverse process(es) of the most caudal lumbar vertebra which may articulate or fuse with the sacrum or ilium and cause isolated L4/5 disc disease. We analysed the elective MR scans of the lumbosacral spine of 769 consecutive patients with low back pain taken between July 2003 and November 2004. Of these 568 showed disc degeneration. Bertolotti’s syndrome was present in 35 patients with a mean age of 32.7 years (15 to 60). This was a younger age than that of patients with multiple disc degeneration, single-level disease and isolated disc degeneration at the L4/5 level (p ≤ 0.05). The overall incidence of Bertolotti’s syndrome in our study was 4.6% (35 of 769). It was present in 11.4% (20 patients) of the under-30 age group. Our findings suggest that Bertolotti’s syndrome must form part of a list of differential diagnoses in the investigation of low back pain in young people

Introduction: Multiple scoring systems are available to evaluate arthritic hip pain and to assess outcome after arthroplasty. These scores focus on evaluating hip pain and function in elderly patients with degenerative joint disease. They are not specific for sports-related or mechanical hip symptoms in young people, or sensitive to change after new treatments such as arthroscopic hip surgery. Methods: We systematically reviewed the literature since 1980, searching for systems used to measure severity of symptoms and outcome of treatment in these patients. We collected reports of performance of these systems. We then used the best of them to collect symptom scores from 200 patients, and measured the agreement of systems. We performed an item reduction process to identify the question items most associated with overall scores. Results: Systematic review yielded 4 scoring systems which have been used to evaluate sports-related or mechanical hip symptoms: the Non-arthritic Hip Score (NHS), Hip Outcome Score (HOS), Hip disability and Osteoarthritis Outcome Score (HOOS)and a modified Harris Hip Score (mHHS). All scores are self administered and symptom related, requiring no physical examination. All but the mHHS have some evidence of reliability and validity. There is a great deal of overlap among the variables selected by the authors and agreement between the various scoring systems is surprisingly good. Most of the variability of all of the systems could be captured with ten simple questions. Conclusion: We have developed a simple set of ten questions which capture outcome information as well as existing more complex systems. This will be useful is assessing outcome after new treatments such as hip arthroscopy in young active people

Aim. Diagnosis of clavicle osteomyelitis (OM) is often difficult with delayed treatment due to the lower incidence of this disease. The present study aimed to summarize clinical experience with clinical features and treatment of clavicle OM. Method. We systematically searched the Pubmed database to identify studies regarding clinical characteristics and management of clavicle OM from 1980 to 2016, with publication language limited to English. Effective data were collected and pooled for analysis. Results. Altogether 69 reports comprising 188 cases were included for analysis. The average age of included patients was 24.95 years, 57.98% of whom were younger than 20 years. According to different etiologies, 86 cases (45.74%) were categorized as infectious OM with 102 cases (54.26%) as noninfectious. Of all the 102 noninfectious OM, 62.13% were diagnosed as chronic recurrent multifocal osteomyelitis (CRMO). The female-to-male ratio of infectious clavicle OM was 1.09, with 3.43 of noninfectious clavicle OM. The most common and earliest clinical symptom was pain, which occurred in 86.81% of the patients. Positive rate of serum erythrocyte sedimentation rate (ESR) was the highest among serum inflammatory biomarkers reported (92.47%). Staphylococcus aureus (46.94%) was the most frequently detected pathogen among patients with infectious clavicle OM. A total of 50 patients received surgical interventions finally (42.37 %). The most frequently used antibiotic was cephalosporin. Most cases achieved favorable outcomes (89.91%). Conclusions. Clavicle OM, classified as infectious and noninfectious, mostly occurred in the young people and females. The most frequently identified clinical symptom was pain. Despite different treatment strategies, most patients could achieve favorable outcomes

Background. Back pain (BP) is a serious problem not only for the elderly, but also young. The non-radiation methods are taking the special relevance in the screening assessment of BP. Objective. To estimate the frequency of occurrence of the BP in young adults and its relation to the functional state of the spine. Methods. The screening conducted 91 medical students (58 women and 33 men) aged 21.3±2.4 years. The research contained a survey on the BP in the last 12 month, and the risk factors, as well as the assessment of functional condition of the spine in three positions using the device ValedoShape (Hocoma, Switzerland). Statistical analysis was performed using Statistica 10.0. Results. A total of 62 (68.1%) students reported BP. In the structure of the BP dominated the lumbar-sacral localization (53.2%). In 90.6% of young people the BP had periodic pattern, 26.7% of students sought medical attention because of the BP. Among the risk factors students mentioned a long stay in a sitting position (51.2%) and weight lifting (35.5%). BP was significantly more frequently among women (71%) and those with scoliosis spine (19.4%). According to the ValedoShape examination the hypermobility of vertebral-motor segment was found in 21 (33.9%) of students with BP, which in 11.3% of the cases had polysegmentary character. Conclusion. 68.1% of young adults had a BP in history. BP was significantly associated with female sex, long-term stay in a sitting position, scoliosis spinal deformity and the loss of segmental integrity (p<0,05)

The femur begins to bow anteriorly at the 200 mm level, but may bow earlier in smaller people. If the stem to be used is less than 200 mm, a straight stem can be used. If the stem is longer than 200 mm, it will perforate the anterior femoral cortex. I know this because I did this on a few occasions more than 20 years ago. To use a long straight stem, there are two techniques. One can either do a diaphyseal osteotomy or one can do a Wagner split (extended trochanteric osteotomy). Both of these will put the knee in some degree of hyperextension, probably insignificant in the elderly, but it may be of significance in the young. In very young people, therefore, it may be preferable to use a bowed stem to avoid this degree of recurvatum. There are two different concepts of loading. Diaphyseal osteotomy implies a proximal loading has been sought. The Wagner split ignores the proximal femur and seeks conical fixation in the diaphysis. There will be very little bone-bone contact between what remains of the attached femur and the detached anterior cortex so that it is important to ensure that the blood supply to the anterior cortex remains intact, preferably by using Wagner's technique, using a quarter-inch osteotome inserted through the vastus to crack the medial cortex. Current modularity is of two types. Distal modularity was attempted many years ago and was never successful. Proximal modularity, as for example, the S-ROM stem, implies various sizes of sleeves fit onto the stem to get a proximal canal fill. In mid-stem modularity, the distal stem wedges into the cone. It has to be driven into where it jams and this can be somewhat unpredictable. For this reason, the solid Wagner stem has been replaced by the mid-stem modular. Once the distal femur is solidly embedded, the proximal body is then selected for height and version. The proximal body is unsupported in the mid-stem modular and initially, few fractures were noted at the taper junction. Cold rolling, shot peening and taper strengthening seem to have solved these problems. There are a variety of types of osteotomy, which can be used for different deformities. With a mid-stem modular system, generally, all that needs to be done is a Wagner-type split and fixation is sought in the mid-diaphysis by conical reaming. No matter what stem is used, distal stability is necessary. This is achieved by flutes, which engage the endosteal cortex. The flutes alone must have sufficient rotational stability to overcome the service loads on the hip of 22 Nm. I divide revision into three categories. In type one, the isthmus is intact, i.e. the bone below the lesser trochanter so that a primary stem can be used. In type two, the isthmus is damaged, i.e. the bone below the lesser trochanter, so a long revision stem is required. In a type three, there is more than 70 mm of missing proximal femur. The Wagner stem may be able to handle this on its own, but most other stems are better supported with a structural allograft cemented to the stem. The reported long term results of mid-stem modular revision implants are good as in most, over 90% survivorship. The introduction of modularity appears to have overcome initial disadvantage of the Wagner stem, i.e. its unpredictability in terms of leg length