Knee osteoarthritis patients with more subchondral cysts have altered tibial subchondral bone mineral density.

BACKGROUND: Subchondral bone cysts are a widely observed, but poorly understood, feature in patients with knee osteoarthritis (OA). Clinical quantitative computed tomography (QCT) has the potential to characterize cysts in vivo but it is unclear which specific cyst parameters (e.g., number, size) are associated with clinical signs of OA, such as disease severity or pain. The objective of this study was to use QCT-based image-processing techniques to characterize subchondral tibial cysts in patients with knee OA and to explore relationships between proximal tibial subchondral cyst parameters and subchondral bone density as well as clinical characteristics of OA (alignment, joint space narrowing (JSN), OA severity, pain) in patients with knee OA. METHODS: The preoperative knee of 42 knee arthroplasty patients was scanned using QCT. Patient characteristics were obtained, including OA severity, knee pain, JSN, and alignment. We used 3D image processing techniques to obtain cyst parameters including: cyst number, cyst number per proximal tibial volume, cyst volume per proximal tibial volume, as well as maximum and average cyst volume across the proximal tibia, as well as regional bone mineral density (BMD) excluding cysts. We used Spearman's correlation coefficients to explore associations between patient characteristics and cyst parameters. RESULTS: At both the medial and lateral compartments of the proximal tibia, greater cyst number and volume were associated with higher BMD. At the lateral region, cyst number and volume were also associated with lateral OA severity, lateral JSN, alignment and sex. Pain was not associated with any cyst parameters at any region. CONCLUSION: Cyst number and volume were associated with BMD at both the medial and lateral compartments. Lateral cyst number and volume were also associated with joint alignment, OA severity, JSN and sex. This is the first study to use clinical QCT to explore subchondral tibial cysts in patients with knee OA and provides further evidence of the relationships between subchondral cysts and clinical OA characteristics.

Natural Course of Local Bone Mineralization After Treatment of Benign or Borderline Bone Tumors and Cysts With a Composite Ceramic Bone Graft Substitute.

After surgical bone tumor removal, filling of the bone defect is frequently performed using a bone graft or bone graft substitute. During follow-up, precise quantification of changes in bone mineral density, within the treated bone defect, is very difficult using conventional X-ray examinations. The objectives of this study were to characterize the pattern of resorption/biodegradation of a composite calcium sulfate/hydroxyapatite bone graft substitute and to quantify the bone defect healing with repeated dual-energy X-ray absorptiometry (DXA) measurements. Seventeen patients treated for 18 benign bone lesions, with subsequent defect filling using 2 variants of a composite ceramic bone graft substitute (CERAMENT™|BONE VOID FILLER or CERMAMENT™|G, BONESUPPORT AB, Lund, Sweden), were scanned postoperatively and after 2, 6, 12, 26, and 52 wk using DXA. After an initial increase in bone mineral density after implantation of the bone graft substitute, bone mineral density decreased in the bone defect region throughout the 52 wk: rapidly in the first 12 wk and slower in the remaining weeks. Despite this continuous decrease, bone mineral density remained, on average, 25% higher in the operated extremity, compared with the nonoperated extremity, after 52 wk. The observed pattern of reduction in bone mineral density is consistent with the anticipated resorption of calcium sulfate within the bone graft substitute during the first 12 wk after surgery. We believe the DXA technique provides a precise method for quantification of bone graft resorption, but for evaluation of new bone formation, 3-dimensional imaging is needed.

Independent association of joint space narrowing, cyst formation and health-related quality of life of patients with hip osteoarthritis in Japan.

INTRODUCTION: This study clarified individual associations of joint space narrowing (JSN) and radiographic features (RF) of hip osteoarthritis (HOA), i.e., cyst and osteophyte formation and subchondral sclerosis, with quality of life (QOL) in Japanese HOA patients. METHODS: This cross-sectional study comprised 117 Japanese HOA patients (98 women, 17 men; mean age, 61.2 years). We recorded locations and the size of each RF and measured JSN on the acetabular side (Ace) or femoral head (FH). We evaluated pain with the Visual Analog Scale (VAS) and assessed QOL with the physical component summary (PCS) and mental component summary (MCS) of the Medical Outcomes Study Short Form-36. We compared QOL with/without the RF on the Ace, FH or both and analyzed relationships between each RF and VAS, PCS and MCS with linear regression analysis. We assessed independent associations of each RF with PCS and MCS with multiple regression analysis using various independent variables. RESULTS: VAS values with the cyst on the Ace only were significantly lower than those with the cyst at both locations. PCS values with the cyst on the Ace only were significantly higher than those for both locations. Independent associations existed for maximum cyst length on the Ace and FH with VAS and for JSN with PCS, but none existed for MCS. CONCLUSIONS: Our study suggested that the location and the size of the cyst formation were associated with both VAS and QOL in Japanese HOA patients. The JSN was independently associated with the PCS.

Magnetic Resonance Imaging Evidence of Postoperative Cyst Formation Does Not Appear to Affect Clinical Outcomes After Autologous Osteochondral Transplantation of the Talus.

PURPOSE: To identify potential cysts using magnetic resonance imaging (MRI) after autologous osteochondral transplantation (AOT) for osteochondral lesions of the talus (OLTs) as well as to determine the effect of cysts on short-term clinical outcomes. METHODS: Eighty-nine MRI scans of 37 patients who had AOT for an OLT were evaluated. Radiographic variables examined included cyst presence, cyst location, bone edema, and cartilage integrity. Patient clinical variables recorded and examined for association with the presence of a cyst included gender, age, preoperative lesion size, size and number of osteochondral graft used, symptoms reported, and pre- and postoperative Foot and Ankle Outcome Score (FAOS) and Short Form-12 (SF-12) scores measured at final follow-up. RESULTS: Twenty-four patients (64.8%) had MRI evidence of cystic change after AOT for an OLT at a mean MRI follow-up time of 15 months after surgery (range 2-54). Patients with presence of a cyst after surgery were older (mean age, 42.7 years) than those without cysts (mean age, 32.7 years) (P = .041), and among patients with a cyst, older patients more often had involvement of the subchondral plate (57.3 v 36.7 years) (P < .001). No other variables associated with cyst formation had statistical significance. Mean patient FAOS scores increased from 50 (±19) preoperatively to 87 (±8) postoperatively. Mean SF-12 scores increased from 52 (±18) preoperatively to 85 (±6) postoperatively. Patients not identified as having a cyst had lower SF-12 (P = .028) and FAOS (P = .032) preoperative scores and more improvement in SF-12 (P = .006) and FAOS (P = .016) scores than patients with cysts. CONCLUSIONS: Postoperative cyst formation on MRI was found to be a common occurrence after AOT for OLT. Although increasing age was related to increased cyst prevalence, the clinical impact of cyst formation was not found to be significant at short-term follow-up. Continued long-term longitudinal follow-up of postoperative cysts is needed. LEVEL OF EVIDENCE: Level IV, prognostic case series.

Simple bone cysts: better with age?

PURPOSE: The purpose of this study was to evaluate whether simple bone cysts (SBC) resolve with age. METHODS: Twenty four subjects with SBC who participated in a prior randomized clinical trial but had not healed at trial conclusion were evaluated for cyst healing. The following clinical and radiographic data were evaluated: age, sex, pain (Visual Analogue Scale), functional health (Short Form 36), subsequent fracture, involved bone, cyst area (cm), distance from physis (cm), endosteal thickening (yes/no), scalloping (no new scalloping/new scalloping), opacity/radiolucency (as is), loculation (yes/no), trabeculation (yes/no), tubulation (yes/no), transition zone (sharp/wide), geographic borders (geographic nonpermeative/nongeographic permeative), radiodense rim (>50%/no rim), and growth plate status (open/closed). Cyst healing was graded as: 1-cyst clearly visible; 2-cyst visible but multilocular and opaque; 3-sclerosis around or within a partially visible cyst; or 4-complete healing with obliteration of cyst. Healing was defined as grade 4. RESULTS: Of 24 subjects, 15 (63%) were male, 18 (75%) cysts were located in the humerus, and 4 (25%) in the femur. Patients were followed for 7.0±1.0 years following initial treatment with a mean age at follow-up of 17.2±3.2 years and 14 (87%) of growth plates were closed. Pain was minimal (0.6/10), function was high (91/100), and none of the patients had experienced subsequent fractures. Although distance from physeal scar had increased (P<0.0001), cyst area reduction (P<0.1) and overall cyst healing (P<0.2) had not changed. Of the 24 subjects, none were graded as healed at time of follow-up. Of the remaining radiographic variables, only decreased loculation (P<0.02) and increased endosteal thickening (P<0.04) showed significant changes. CONCLUSION: Despite the assumption that most SBC will resolve with skeletal maturity, this study indicates that none of the cysts were graded as completely healed although 87% of growth plates were closed. SIGNIFICANCE: Growth plate closure may not signify healing of SBC and although symptoms and fractures are rare, further studies are needed to follow patients with SBC through early adulthood.

[Phenomenon of remodeling and adjustment the topology of the calcaneus with a solitary cyst--case report]. / Zjawiska remodelingu i dostosowania topologii w kosci pietowej z torbiela samotna--opis przypadku.

Solitary cyst is a place of osteolytic bone loss. In this paper presents the biomechanical aspect of the remodeling and adaptation of the topology of the calcaneus suffering from this disease, which leads to the avoidance of pathological fracture.

Injection of demineralized bone matrix with bone marrow concentrate improves healing in unicameral bone cyst.

BACKGROUND: Unicameral bone cysts are benign lesions that usually spontaneously regress with skeletal maturity; however, the high risk of pathologic fractures often justifies treatment that could reinforce a weakened bone cortex. Various treatments have been proposed but there is no consensus regarding the best procedure. QUESTIONS/PURPOSES: We compared the healing rates and failures of two methods of cure based on multiple injections of corticosteroid or a single injection of demineralized bone matrix (DBM) in association with bone marrow concentrate (BMC). METHODS: We retrospectively reviewed 184 patients who had one of the two treatments for unicameral bone cysts with cortical erosion. Clinical records were reviewed for treatment failures and radiographs for healing in all patients. The minimum followup was 12 months for the Steroids Group (mean, 48 months; range, 12-120 months) and 12 months for the DBM + BMC Group (mean, 20 months; range, 12-28 months). RESULTS: After one treatment we observed a lower healing rate of cysts treated with multiple injections of steroids compared with the healing after the first injection of DBM + BMC (21% versus 58%, respectively). At last followup, 38% healed with steroids and 71% with DBM + BMC. The rate of failure after one steroid injection was higher than after a single injection of BDM + BMC (63% versus 24%, respectively). We observed no difference in fracture rates after treatment between the two groups. CONCLUSIONS: A single injection of DBM added with autologous bone marrow concentrate appears to provide a higher healing rate with a lower number of failures compared with a single injection of steroids.

MRI-identified abnormalities and wrist range of motion in asymptomatic versus symptomatic computer users.

BACKGROUND: Previous work has shown an association between restricted wrist range of motion (ROM) and upper extremity musculoskeletal disorders in computer users. We compared the prevalence of MRI-identified wrist abnormalities and wrist ROM between asymptomatic and symptomatic computer users. METHODS: MR images at 1.5 T of both wrists were obtained from 10 asymptomatic controls (8 F, 2 M) and 14 computer users (10 F, 4 M) with chronic wrist pain (10 bilateral; 4 right-side). Maximum wrist range of motion in flexion and radioulnar deviation was measured with an electrogoniometer. RESULTS: Extraosseous ganglia were identified in 66.6% of asymptomatic wrists and in 75% of symptomatic wrists. Intraosseous ganglia were identified in 45.8% of asymptomatic wrists and in 75% of symptomatic wrists, and were significantly (p < .05) larger in the symptomatic wrists. Distal ECU tendon instability was identified in 58.4% of both asymptomatic and symptomatic wrists. Dominant wrist flexion was significantly greater in the asymptomatic group (68.8 ± 6.7 deg.) compared to the symptomatic group (60.7 ± 7.3 deg.), p < .01. There was no significant correlation between wrist flexion and intraosseous ganglion burden (p = .09) CONCLUSIONS: This appears to be the first MRI study of wrist abnormalities in computer users.This study demonstrates that a variety of wrist abnormalities are common in computer users and that only intraosseous ganglia prevalence and size differed between asymptomatic and symptomatic wrists. Flexion was restricted in the dominant wrist of the symptomatic group, but the correlation between wrist flexion and intraosseous ganglion burden did not reach significance. Flexion restriction may be an indicator of increased joint loading, and identifying the cause may help to guide preventive and therapeutic interventions.

The natural history of osteochondral lesions in the ankle.

Most osteochondral lesions (defects) of the talar dome are caused by trauma, which may be a single event or repeated, less intense events (microtrauma). A lesion may heal, remain asymptomatic, or progress to deep ankle pain on weight bearing, prolonged joint swelling, and the formation of subchondral bone cysts. During loading, compression of the cartilage forces water into the microfractured subchondral bone. The increased flow and pressure of fluid in the subchondral bone can cause osteolysis and the slow development of a subchondral cyst. The pain does not arise from the cartilage lesion but most likely is caused by repetitive high fluid pressure during walking and a concomitant decrease in pH produced by osteoclasts, which sensitize the highly innervated subchondral bone. Prevention of further degeneration depends on several factors, including the repair of the subchondral bone plate and the correct alignment of the ankle joint.

Osteochondral defects in the ankle: why painful?

Osteochondral defects of the ankle can either heal and remain asymptomatic or progress to deep ankle pain on weight bearing and formation of subchondral bone cysts. The development of a symptomatic OD depends on various factors, including the damage and insufficient repair of the subchondral bone plate. The ankle joint has a high congruency. During loading, compressed cartilage forces its water into the microfractured subchondral bone, leading to a localized high increased flow and pressure of fluid in the subchondral bone. This will result in local osteolysis and can explain the slow development of a subchondral cyst. The pain does not arise from the cartilage lesion, but is most probably caused by repetitive high fluid pressure during walking, which results in stimulation of the highly innervated subchondral bone underneath the cartilage defect. Understanding the natural history of osteochondral defects could lead to the development of strategies for preventing progressive joint damage.

Assessment of spontaneous resolution of idiopathic bone cavity.

Idiopathic Bone Cavity (IBC) or Simple Bone Cyst (SBC) is a non- epithelialized bone cavity with serosanguinous fluid content or empty. There is a literature debate regarding its pathogenesis that remains unclear. The main treatment option is the surgical exploration, although there are successful cases described in the literature in which just a follow-up with clinical and radiographic evaluation was performed. Objective This study aimed to assess the spontaneous resolution of idiopathic bone cavity untreated by surgery. Material and Methods Twenty-one patients diagnosed with surgically untreated IBC were submitted to a follow-up protocol modified from Damante, Guerra, and Ferreira5 (2002). A clinical and radiographic evaluation was performed in 13 patients (13/21), while eight patients (8/21) were only radiographically evaluated. Three observers evaluated the panoramic radiographs of 21 patients and the Kappa test was performed by intra and inter-examiners. Inductive and descriptive statistics were applied to the results. Results Only one patient had a positive response to palpation and percussion of the teeth in the cyst area. Most of the cysts evaluated were rated as 3 (lesion "in involution"), 4 (lesion "almost completely resolved"), or 5 ("completely resolved"). Conclusions We observed progressive spontaneous resolution of IBC. Most cysts were found in the recovery process in different follow-up periods. Patient's follow-up, without surgery, may be considered after the diagnosis based on epidemiological, clinical, and radiographic features of the lesion.

Is subchondral bone cyst formation in non-load-bearing region of osteoarthritic knee a vascular problem?

Subchondral bone cyst is common in the progressive knee osteoarthritis yet its underlying mechanism remains unclear. In addition to the existing theories such as synovial fluid influx and mechanical contusion, we identified the potential link between vascular pathology and osteoarthritic bone pathologies including cystic lesion formation, particularly in the non-load-bearing region. This new hypothesis for SBC formation in non-load-bearing region for knee, which cannot be explained by the existing theories, will provide us a new angle to understand the pathomechanism and pathophysiology of subchondral bone disturbance in osteoarthritis in addition to the classical biomechanical overloading theories. It might guide us to develop a novel diagnostic and therapeutic approach to treat progressive osteoarthritis via targeting vascular pathology.

Bone cyst formation after ankle arthroplasty may be caused by stress shielding. A numerical simulation of the strain adaptive bone remodelling.

BACKGROUND: The history of total ankle arthroplasty (TAA) has different evolution steps to improve the outcome. The third generation implants show an overall 8-year survival rate up to 93%. The main reported reason for early failure of TAA is aseptic loosening, cyst formation is also frequently reported. The aim of the present study is to use the finite element (FE) method to analyze the adaptive bone remodeling processes, including cyst formation after TAA. METHODS: Bone characteristics applied to the model corresponded to information obtained from computed tomography. Finite element models for the tibia and the talus were developed and implant components were virtually implanted. RESULTS: The calculated total bone loss is 2% in the tibia and 17% in the talus. Cysts and areas of increased bone density were detectable dependent on prosthesis design in the tibia and talus. CONCLUSION: Our FE simulation provides a theoretical explanation for cyst formation and increasing bone density depending on implant design. However, cysts are not mono-causal, histo-chemical reactions should also be considered. Further clinical studies are necessary to evaluate the relevance of cyst formation and therapeutic strategies.

Bony findings detected by MRI may reflect the pathophysiology of osteoarthritis with thumb carpometacarpal joint pain.

BACKGROUND: Osteoarthritis (OA) is the most common skeletal disease worldwide. Although thumb carpametacarpal joint (CMJ) OA is also frequently encountered, the etiologies remain largely unknown. METHOD: We analyzed 20 patients who had thumb CMJ OA with accompanying joint pain and categorized a total of 37 thumbs according to the Eaton and Littler staging system. RESULTS: In patients with advanced OA, bone alterations as detected by magnetic resonance imaging (MRI) were observed in almost all of the painful joints. The frequency of bone alterations in the thumb CMJ increased with OA severity. In contrast, MRI revealed no bone alterations in thumbs with no pain and less pain in bilateral thumb basal pain, even in radiographically advanced OA. CONCLUSIONS: While the incidence of bone cysts in the CMJ was higher with OA staging, OA severity had no apparent correlation with pain. Thus, it is possible that the cause of thumb CMJ pain in advanced OA is bone alterations.

Suprascapular nerve entrapment caused by an intraosseous ganglion of the scapula: A case report.

RATIONALE: Suprascapular nerve compression is a rare but important entity that is often missed in clinical practice. Nerve dysfunction caused by an intraosseous ganglion of the glenoid is extremely rare, to the best of our knowledge, only 1 case of suprascapular nerve entrapment due to an intraosseous ganglion cyst has been reported previously in the published literature. PATIENT CONCERNS: We report a 61-year-old woman who had complained right shoulder pain that lasted over 3 years which was exacerbated by overhead activities. DIAGNOSES: We diagnosed it as suprascapular nerve entrapment at the spinoglenoid notch caused by an intraosseous ganglion of the scapula. INTERVENTIONS: Plain X-ray, computed tomography, magnetic resonance imaging (MRI), and electromyography (EMG) of the shoulder. OUTCOMES: She undertook surgical excision with curettage of the cyst. The infraspinatus fossa dull pain subsided immediately after surgery. No recurrence of the cystic lesion was noted on follow-up plain radiograph and MRI performed 18 months postoperatively. Shoulder external rotation strength was graded as 5 of 5. LESSIONS: Intraosseous ganglion of the glenoid can cause compression of the suprascapular nerve when the lesion is expanded toward the spinoglenoid notch. The EMG study confirmed compression of the suprascapular nerve. The patient showed clinical and radiologic improvement after surgical decompression with no recurrence.

Outcome of osteochondral autograft transplantation for type-V cystic osteochondral lesions of the talus.

The treatment of osteochondral lesions of the talus has evolved with the development of improved imaging and arthroscopic techniques. However, the outcome of treatment for large cystic type-V lesions is poor, using conventional grafting, debridement or microfracture techniques. This retrospective study examined the outcomes of 50 patients with a cystic talar defect who were treated with arthroscopically harvested, cored osteochondral graft taken from the ipsilateral knee. Of the 50 patients, 45 (90%) had a mean good to excellent score of 80.3 (52 to 90) in the Karlsson-Peterson Ankle Score, at a mean follow-up of 36 months (24 to 83). A malleolar osteotomy for exposure was needed in 26 patients and there were no malleolar mal- or nonunions. One patient had symptoms at the donor site three months after surgery; these resolved after arthroscopic release of scar tissue. This technique is demanding with or without a malleolar osteotomy, but if properly performed has a high likelihood of success.

Is retrograde drilling really useful for osteochondral lesion of talus with subchondral cyst?: A case report.

RATIONALE: Retrograde drilling is a well accepted procedure for osteochondral lesion of the talus and subchondral cyst with intact overlying cartilage. It has good results in most reports. Compared to anterograde drilling, retrograde drilling can protect the integrity of the articular cartilage. The purpose of this study was to evaluate the suitability of using retrograde drilling for osteochondral lesion with subchondral cyst and discuss the mechanism involved in the development of subchondral cyst. PATIENT CONCERNS: We report a 53-year-old man who had complained left ankle pain that lasted over 6 months which was exacerbated by walking. DIAGNOSES: We diagnosed it as osteochondral lesion of the talus with subchondral cyst. INTERVENTIONS: Plain X-ray, computed tomography, and magnetic resonance imaging (MRI) of the ankle. OUTCOMES: He undertook retrograde drilling without debridement of cartilage. After the surgery, the pain had been subsided for 1 year, although arthritic change had progressed. However, after 5 years of retrograde drilling, he revisited our hospital due to severe ankle pain. Plain X-ray and MRI showed arthritic change of the ankle and multiple cystic formation of talus. LESSONS: Retrograde drilling has some problem because this procedure is not theoretically correct when the development of a subchondral cyst in osteochondral lesion of the talus is considered. In addition, retrograde drilling may impair uninjured bone marrow of the talus, resulting in the development of multiple cystic formations.

Cysts, geodes, and erosions.

Subchondral cystic lesions are common features that are associated with many arthropathies and synovial-based processes. Although not comprehensive in scope, this article correlated the pathophysiology and imaging features of several of these disorders to better understand the associated subchondral lucencies. The imaging features of these subchondral cystic lesions were described in each process, and, in some cases, demonstrated overlapping features. By becoming familiar with the disease processes and recognizing the imaging appearances and associated clinical findings, the radiologist will be better able to differentiate these benign entities from more aggressive processes, such as tumor. Subchondral cystic lesions are common features that are associated with many arthropathies and synovial-based processes. Although not comprehensive in scope, this article correlated the pathophysiology and imaging features of several of these disorders to better understand the associated subchondral lucencies. The imaging features of these subchondral cystic lesions were described in each process, and, in some cases, demonstrated overlapping features. By becoming familiar with the disease processes and recognizing the imaging appearances and associated clinical findings, the radiologist will be better able to differentiate these benign entities from more aggressive processes, such as tumor.

Treatment of active unicameral bone cysts with percutaneous injection of demineralized bone matrix and autogenous bone marrow.

BACKGROUND: The treatment of unicameral bone cysts varies from open bone-grafting procedures to percutaneous injection of corticosteroids or bone marrow. The purpose of this study was to evaluate the feasibility and effectiveness of percutaneous injection of a mixture of demineralized bone matrix and autogenous bone marrow for the treatment of simple bone cysts. METHODS: Twenty-three patients with an active unicameral bone cyst were treated with trephination and injection of allogeneic demineralized bone matrix and autogenous bone marrow. The patients were followed for an average of fifty months (range, thirty to eighty-one months), at which time pain, function, and radiographic signs of resolution of the cyst were assessed. RESULTS: The average time until the patients had pain relief was five weeks, and the average time until the patients returned to full, unrestricted activities was six weeks. Bone-healing at the site of the injection was first seen radiographically at three to six months. No patient had a pathologic fracture during this early bone-healing stage. Cortical remodeling was seen radiographically by six to nine months, and after one year the response was usually complete, changing very little from then on. Five patients required a second injection because of recurrence of the cyst, and all five had a clinically and radiographically quiescent cyst after an average of thirty-six additional months of follow-up. Seven of the twenty-three patients had incomplete healing manifested by small, persistent radiolucent areas within the original cyst. None of these cysts increased in size or resulted in pain or fracture. CONCLUSIONS: Percutaneous injection of allogeneic demineralized bone matrix and autogenous bone marrow is an effective treatment for unicameral bone cysts.

The aetiology and treatment of simple bone cysts.

The internal pressure of simple bone cysts was found to be slightly higher than the normal pressure of the bone marrow in the contralateral limb. The pressure within the cyst was measured during drilling with a Kirschner wire; it gradually decreased as the number of drill-holes increased. The PO2 of the cyst fluid was markedly lower than that of either venous or arterial blood measured synchronously. It is suggested that venous obstruction in the bone is the likely cause of these cysts. Seven patients with simple bone cysts were treated by the multiple drill-hole method, and the clinical outcome was excellent. Multiple drilling may prove to be the treatment of choice for simple bone cysts in the younger patient, as it presents fewer hazards than other procedures.